Simplify release workflow

[martincostello]

With #3502, the release draft can be created in one request, rather than generating the notes and then manually editing them.

[Copilot]

Pull Request Overview

This PR simplifies the GitHub release workflow by utilizing the built-in generate_release_notes parameter instead of manually generating and filtering release notes. The change reduces code complexity by eliminating the separate API call to generate notes and the manual filtering logic.

• Removes manual release notes generation and filtering logic
• Uses the built-in generate_release_notes parameter in the createRelease API call
• Extracts target_commitish into a variable for better code organization

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.28%. Comparing base (3cba1fd) to head (29f6b07).
Report is 1 commits behind head on master.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3503   +/-   ##
=======================================
  Coverage   94.28%   94.28%           
=======================================
  Files         110      110           
  Lines        3816     3816           
  Branches      722      722           
=======================================
  Hits         3598     3598           
  Misses        218      218           

Flag	Coverage Δ
Linux	94.28% <ø> (ø)
Windows	94.28% <ø> (ø)
macOS	94.28% <ø> (ø)

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