Prepare for 7.3.0 Release

[azeey]

🎈 Release

Preparation for 7.3.0 release.

Comparison to 7.2.0: gz-sensors7_7.2.0...gz-sensors7

Checklist

• Asked team if this is a good time for a release
• There are no changes to be ported from the previous major version
• No PRs targeted at this major version are close to getting in
• Bumped minor for new features, patch for bug fixes
• Updated changelog
• Updated migration guide (as needed)
• Link to PR updating dependency versions in appropriate repository in gazebo-release (as needed):

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 #386 (108eb60) into gz-sensors7 (7b4387f) will not change coverage.
The diff coverage is n/a.

❗ Current head 108eb60 differs from pull request most recent head 2ecddc6. Consider uploading reports for the commit 2ecddc6 to get more accurate results

@@             Coverage Diff              @@
##           gz-sensors7     #386   +/-   ##
============================================
  Coverage        69.73%   69.73%           
============================================
  Files               36       36           
  Lines             3962     3962           
============================================
  Hits              2763     2763           
  Misses            1199     1199