Update test config to run ogre 1.x tests in ign-rendering6 on macOS

[iche033]

🦟 Bug fix

tests started failing after updating our ign-rendering6 homebrew formula to depend on ogre 2.2:
osrf/homebrew-simulation#1574

There should be some GL3+ support for ogre 2.2 on macOS as seen in:
OGRECave/ogre-next#209

But updated to run ogre 1.x tests until we have time to investigate the cause of failing tests on macOS.

I also fixed some clang warnings.

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• 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

[codecov]

Codecov Report

Merging #407 (ce889dd) into main (993bb0b) will not change coverage.
The diff coverage is n/a.

❗ Current head ce889dd differs from pull request most recent head 94dbc51. Consider uploading reports for the commit 94dbc51 to get more accurate results

@@           Coverage Diff           @@
##             main     #407   +/-   ##
=======================================
  Coverage   58.65%   58.65%           
=======================================
  Files         174      174           
  Lines       17278    17278           
=======================================
  Hits        10134    10134           
  Misses       7144     7144           

Impacted Files	Coverage Δ
ogre2/src/Ogre2DepthCamera.cc	87.10% <ø> (ø)
ogre2/src/Ogre2ThermalCamera.cc	89.51% <ø> (ø)

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[chapulina]

7 failures is better than 42 🙃