feat(ci): Replace deprecated TeXLive action with working alternative

[Meatball-Sub-11]

Description of Changes:

This PR fixes the failing CI build by replacing the deprecated teatimeguest/setup-texlive-action@v3 with the actively maintained TeX-Live/setup-texlive-action@v3.

Changes made:

• Updated .github/workflows/ci.yml line 59 to use TeX-Live/setup-texlive-action@v3 instead of the deleted teatimeguest/setup-texlive-action@v3
• All existing TeXLive package configurations remain unchanged
• Maintains full API compatibility with existing workflow

Aim/Goal of Changes:

The primary goal is to restore the CI pipeline functionality by resolving the action lookup failure. The current workflow was failing with the error:

Error: An action could not be found at the URI 'https://api.github.com/repos/teatimeguest/setup-texlive-action/tarball/ff7075d1802f73f131689d381f345a8dc5a5000'

This change ensures:

• ✅ CI builds can run successfully
• ✅ PDF and ePUB generation continues to work
• ✅ All TeXLive packages are installed correctly
• ✅ No breaking changes to existing functionality

How to Test/Verify:

1. Verify CI Pipeline: Push this branch and confirm the GitHub Actions workflow runs without the TeXLive action error
2. Check Build Artifacts: Ensure that all build artifacts are generated successfully:
   • HTML book output
   • PDF with cover (100-exercises-to-learn-rust.pdf)
   • Paperback PDF version
   • ePUB format
3. Validate TeXLive Installation: Confirm the tlmgr --version step succeeds
4. Test Package Installation: Verify all required TeXLive packages are installed correctly

Expected behavior after fix:

• CI workflow completes successfully without action resolution errors
• All existing TeXLive packages continue to be installed
• Book generation (HTML, PDF, ePUB) works as before

Request for Review:

Please review the changes for clarity, correctness and adherence to project goals. This is a straightforward replacement of a deprecated GitHub Action with its official successor, maintaining full backward compatibility while fixing the CI build failure.

Additional Context:

The TeX-Live/setup-texlive-action@v3 is the official replacement maintained by the TeX-Live organization and is specifically documented as "a temp replacement for the deleted teatimeguest/setup-texlive-action". It uses the same input parameters and maintains identical functionality.

[LukeMathWalker]

Thank you!