Remove ignition

[nkoenig]

🎉 New feature

Removes ignition

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• 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]

Codecov Report

Merging #367 (11cc58d) into main (241b06e) will increase coverage by 1.22%.
The diff coverage is 100.00%.

❗ Current head 11cc58d differs from pull request most recent head 92cf0b0. Consider uploading reports for the commit 92cf0b0 to get more accurate results

@@            Coverage Diff             @@
##             main     #367      +/-   ##
==========================================
+ Coverage   95.71%   96.93%   +1.22%     
==========================================
  Files           9        9              
  Lines        1073     1045      -28     
==========================================
- Hits         1027     1013      -14     
+ Misses         46       32      -14     

Files Changed	Coverage Δ
src/Generator.cc	93.50% <ø> (ø)
include/gz/msgs/Factory.hh	100.00% <100.00%> (+28.57%)	⬆️
src/Factory.cc	89.88% <100.00%> (+7.64%)	⬆️

[mjcarroll]

I think this one we can actually target at harmonic if we don't do the version bumps. msgs is already being bumped for harmonic, though.

[nkoenig]

I think this one we can actually target at harmonic if we don't do the version bumps. msgs is already being bumped for harmonic, though.

There are no API/ABI breaking changes, but there is a behavior change. gz-msgs9 will output deprecation warnings, for example.

[mjcarroll]

Focal CI isn't going to run here (removed from this branch), so this is good to go.