ForwardPort #2388 Fix unused gcc warnings

[Blast545]

🦟 Bug fix

Fixes gcc warnings appearing in CI: https://build.osrfoundation.org/job/gz_sim-ci-main-jammy-amd64/66/gcc/

Summary

Forward port to fix warnings on main

Checklist

• [ ] Signed all commits for DCO
• [ ] Added tests
• [ ] Updated documentation (as needed)
• [ ] Updated migration guide (as needed)
• [ ] Consider updating Python bindings (if the library has them)
• [ ] codecheck passed (See contributing)
• [ ] All tests passed (See test coverage)
• [ ] While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 65.94%. Comparing base (098085b) to head (6dfb9ed). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2395 +/- ## ========================================== - Coverage 65.95% 65.94% -0.01% ========================================== Files 327 327 Lines 31319 31318 -1 ========================================== - Hits 20655 20654 -1 Misses 10664 10664 ```

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