Remove Bionic from future releases (Garden+)

[chapulina]

• See Garden support gazebo-tooling/release-tools#597

Summary

ign-gui7 will be on Garden.

Test it

No Bionic builds should be triggered.

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• 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 and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸

[codecov]

Codecov Report

Merging #371 (185b936) into main (63b3599) will decrease coverage by 0.00%.
The diff coverage is n/a.

❗ Current head 185b936 differs from pull request most recent head d00cd15. Consider uploading reports for the commit d00cd15 to get more accurate results

@@            Coverage Diff             @@
##             main     #371      +/-   ##
==========================================
- Coverage   63.84%   63.83%   -0.01%     
==========================================
  Files          45       45              
  Lines        5462     5459       -3     
==========================================
- Hits         3487     3485       -2     
+ Misses       1975     1974       -1     

Impacted Files	Coverage Δ
src/plugins/scene3d/Scene3D.cc	49.56% <0.00%> (-0.07%)	⬇️
src/plugins/minimal_scene/MinimalSceneRhiOpenGL.cc	96.47% <0.00%> (+1.06%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 63b3599...d00cd15. Read the comment docs.

[jennuine]

I believe we can suppress Windows warnings with #pragma warning(disable : 4834) in PointCloud.cc: https://docs.microsoft.com/en-us/cpp/error-messages/compiler-warnings/c4834?view=msvc-170

[chapulina]

I believe we can suppress Windows warnings with #pragma warning(disable : 4834) in PointCloud.cc:

Thanks! I'll open a separate PR for this