Product Gallery Thumbnails: Fix thumbnails cropping

[danieldudzic]

Describe the bug

When #11665 is merged, the thumbnails will no longer be always cropped.

The thumbnails should also follow the Crop images to fit setting value.

To reproduce

Steps to reproduce the behavior:

1. With a block theme, open Appearance > Editor.
2. Open Templates > Single Product.
3. Select Convert to Blocks if you are using the Classic Templates.
4. Add the Product Gallery block.
5. Ensure the Thumbnails are enabled.
6. Change the Crop images to fit value, notice the thumbnails are never cropped.

Expected behavior

When Crop images to fit is enabled, the thumbnails should be cropped to square.

When Crop images to fit is disabled the thumbnails should not be cropped to square.

Screenshots