Narrow some ImageSlide property types

ImageSlide is hardcoded to a single level, and the level_count property
and get_best_level_for_downsample() return types already reflect this.
Reduce the level_dimensions() and level_downsamples() return types to
1-tuples.  In the latter case we can't reduce to a Literal because literal
floats are disallowed.

Signed-off-by: Benjamin Gilbert <bgilbert@cs.cmu.edu>

Author: bgilbert

openslide/__init__.py

@@ -402,7 +402,7 @@ def level_count(self) -> Literal[1]:
         return 1
 
     @property
-    def level_dimensions(self) -> tuple[tuple[int, int], ...]:
+    def level_dimensions(self) -> tuple[tuple[int, int]]:
         """A list of (width, height) tuples, one for each level of the image.
 
         level_dimensions[n] contains the dimensions of level n."""
@@ -411,7 +411,7 @@ def level_dimensions(self) -> tuple[tuple[int, int], ...]:
         return (self._image.size,)
 
     @property
-    def level_downsamples(self) -> tuple[float, ...]:
+    def level_downsamples(self) -> tuple[float]:
         """A list of downsampling factors for each level of the image.
 
         level_downsample[n] contains the downsample factor of level n."""