Docs: fix misleading negative prompt argument desc in SD3 pipeline

src/diffusers/pipelines/controlnet_sd3/pipeline_stable_diffusion_3_controlnet.py

@@ -399,8 +399,8 @@ def encode_prompt(
             do_classifier_free_guidance (`bool`):
                 whether to use classifier free guidance or not
             negative_prompt (`str` or `list[str]`, *optional*):
-                The prompt or prompts not to guide the image generation. If not defined, one has to pass
-                `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
+                The prompt or prompts not to guide the image generation. If not defined, it defaults to an
+                empty string. Alternatively, one can pass `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
                 less than `1`).
             negative_prompt_2 (`str` or `list[str]`, *optional*):
                 The prompt or prompts not to guide the image generation to be sent to `tokenizer_2` and

src/diffusers/pipelines/controlnet_sd3/pipeline_stable_diffusion_3_controlnet_inpainting.py

@@ -421,8 +421,8 @@ def encode_prompt(
             do_classifier_free_guidance (`bool`):
                 whether to use classifier free guidance or not
             negative_prompt (`str` or `list[str]`, *optional*):
-                The prompt or prompts not to guide the image generation. If not defined, one has to pass
-                `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
+                The prompt or prompts not to guide the image generation. If not defined, it defaults to an
+                empty string. Alternatively, one can pass `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
                 less than `1`).
             negative_prompt_2 (`str` or `list[str]`, *optional*):
                 The prompt or prompts not to guide the image generation to be sent to `tokenizer_2` and

src/diffusers/pipelines/pag/pipeline_pag_sd_3.py

@@ -369,8 +369,8 @@ def encode_prompt(
             do_classifier_free_guidance (`bool`):
                 whether to use classifier free guidance or not
             negative_prompt (`str` or `list[str]`, *optional*):
-                The prompt or prompts not to guide the image generation. If not defined, one has to pass
-                `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
+                The prompt or prompts not to guide the image generation. If not defined, it defaults to an
+                empty string. Alternatively, one can pass `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
                 less than `1`).
             negative_prompt_2 (`str` or `list[str]`, *optional*):
                 The prompt or prompts not to guide the image generation to be sent to `tokenizer_2` and

src/diffusers/pipelines/pag/pipeline_pag_sd_3_img2img.py

@@ -385,8 +385,8 @@ def encode_prompt(
             do_classifier_free_guidance (`bool`):
                 whether to use classifier free guidance or not
             negative_prompt (`str` or `list[str]`, *optional*):
-                The prompt or prompts not to guide the image generation. If not defined, one has to pass
-                `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
+                The prompt or prompts not to guide the image generation. If not defined, it defaults to an
+                empty string. Alternatively, one can pass `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
                 less than `1`).
             negative_prompt_2 (`str` or `list[str]`, *optional*):
                 The prompt or prompts not to guide the image generation to be sent to `tokenizer_2` and

src/diffusers/pipelines/stable_diffusion_3/pipeline_stable_diffusion_3.py

@@ -378,8 +378,8 @@ def encode_prompt(
             do_classifier_free_guidance (`bool`):
                 whether to use classifier free guidance or not
             negative_prompt (`str` or `list[str]`, *optional*):
-                The prompt or prompts not to guide the image generation. If not defined, one has to pass
-                `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
+                The prompt or prompts not to guide the image generation. If not defined, it defaults to an
+                empty string. Alternatively, one can pass `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
                 less than `1`).
             negative_prompt_2 (`str` or `list[str]`, *optional*):
                 The prompt or prompts not to guide the image generation to be sent to `tokenizer_2` and
@@ -837,8 +837,8 @@ def __call__(
                 `guidance_scale > 1`. Higher guidance scale encourages to generate images that are closely linked to
                 the text `prompt`, usually at the expense of lower image quality.
             negative_prompt (`str` or `list[str]`, *optional*):
-                The prompt or prompts not to guide the image generation. If not defined, one has to pass
-                `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
+                The prompt or prompts not to guide the image generation. If not defined, it defaults to an
+                empty string. Alternatively, one can pass `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
                 less than `1`).
             negative_prompt_2 (`str` or `list[str]`, *optional*):
                 The prompt or prompts not to guide the image generation to be sent to `tokenizer_2` and

src/diffusers/pipelines/stable_diffusion_3/pipeline_stable_diffusion_3_img2img.py

@@ -404,8 +404,8 @@ def encode_prompt(
             do_classifier_free_guidance (`bool`):
                 whether to use classifier free guidance or not
             negative_prompt (`str` or `list[str]`, *optional*):
-                The prompt or prompts not to guide the image generation. If not defined, one has to pass
-                `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
+                The prompt or prompts not to guide the image generation. If not defined, it defaults to an
+                empty string. Alternatively, one can pass `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
                 less than `1`).
             negative_prompt_2 (`str` or `list[str]`, *optional*):
                 The prompt or prompts not to guide the image generation to be sent to `tokenizer_2` and

src/diffusers/pipelines/stable_diffusion_3/pipeline_stable_diffusion_3_inpaint.py

@@ -410,8 +410,8 @@ def encode_prompt(
             do_classifier_free_guidance (`bool`):
                 whether to use classifier free guidance or not
             negative_prompt (`str` or `list[str]`, *optional*):
-                The prompt or prompts not to guide the image generation. If not defined, one has to pass
-                `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
+                The prompt or prompts not to guide the image generation. If not defined, it defaults to an
+                empty string. Alternatively, one can pass `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
                 less than `1`).
             negative_prompt_2 (`str` or `list[str]`, *optional*):
                 The prompt or prompts not to guide the image generation to be sent to `tokenizer_2` and