Fixes #26092.

This PR fixes an issue where RGB images passed with an alpha array were falling back to for alpha resampling. This introduced an implicit optional dependency on for this feature, causing it to fail or behave inconsistently if was not present or if the fallback failed.

Changes:

• Replaced with , leveraging Matplotlib's internal C-based resampling (images module).
• This aligns the RGB alpha path with the existing grayscale image alpha path.
• Removed the import and usage in .

Verification:

• Verified with a reproduction script that mocks (simulating missing dependency).
• Confirmed correct alpha values are produced in the output image.