Remove deprecated 'convert' parameter from optimize_image (Fixes #292)

[Sriram-Nambiar]

Fixes #292

Summary of Changes:

• Removed deprecated convert parameter from optimize_image() and removed unused warnings import.
• Removed deprecation test cases from tests/image/test_image.py.
• Added entry in CHANGELOG.md under [Unreleased] -> Removed.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (9b47195) to head (74d2535).
⚠️ Report is 8 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #350   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           42        42           
  Lines         2708      2703    -5     
  Branches       401       399    -2     
=========================================
- Hits          2708      2703    -5     

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[benoit74]

Please ensure code coverage is still 100%

[Sriram-Nambiar]

I'm out at the moment will fix the coverage gap and update the PR soon

[benoit74]

Converting to draft, LGTM but we need to wait for a major release to be planned before merging this. Thank you!