Fix upsample half pixel mode for size one

[PrithviBadiga]

Fixes the ATen upsampling lowering for align_corners=False to use ONNX half_pixel mode instead of pytorch_half_pixel.

pytorch_half_pixel special-cases output size 1 differently from PyTorch eager behavior, causing mismatches for cases like upsample_bilinear2d(..., output_size=(1, 1), align_corners=False). This change makes the exported Resize node match PyTorch results for that edge case.

Adds regression samples for 2D upsampling with output size 1, covering both upsample_bilinear2d and upsample_bilinear2d.vec.

[PrithviBadiga]

@microsoft-github-policy-service agree

[PrithviBadiga]

@PrithviBadiga please read the following Contributor License Agreement(CLA). If you agree with the CLA, please reply with the following information.

@microsoft-github-policy-service agree [company="{your company}"]

Options:

• (default - no company specified) I have sole ownership of intellectual property rights to my Submissions and I am not making Submissions in the course of work for my employer.

@microsoft-github-policy-service agree

• (when company given) I am making Submissions in the course of work for my employer (or my employer has intellectual property rights in my Submissions by contract or applicable law). I have permission from my employer to make Submissions and enter into this Agreement on behalf of my employer. By signing below, the defined term “You” includes me and my employer.

@microsoft-github-policy-service agree company="Microsoft"

Contributor License Agreement

@microsoft-github-policy-service agree