Enable new CMake policy to fix protobuf compilation

[Blast545]

Signed-off-by: Jorge Perez [email protected]

🦟 Bug fix

Fixes #990

Summary

Discussion is provided in the original ticket.

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

[chapulina]

LGTM with happy CI.

[codecov]

Codecov Report

Merging #1046 (b165657) into main (f4d47b5) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1046      +/-   ##
==========================================
- Coverage   63.71%   63.70%   -0.01%     
==========================================
  Files         257      257              
  Lines       20064    20064              
==========================================
- Hits        12783    12782       -1     
- Misses       7281     7282       +1     

Impacted Files	Coverage Δ
src/EntityComponentManager.cc	84.95% <0.00%> (-0.15%)	⬇️

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[Blast545]

Both of these jobs run on top of this PR: https://build.osrfoundation.org/job/ign_gazebo-pr-win/3151/ and https://build.osrfoundation.org/job/ign_gazebo-pr-win/3154/ and neither have the Protobuf CMake error.

I think this is ready to merge and backport, I'll keep an eye to CI after this is merged as well.