Prepare for 14.0.0 Release

[azeey]

🎈 Release

Preparation for 14.0.0 release.

Comparison to 14.0.0-pre3: sdformat14_14.0.0-pre3...sdf14

Needed by <PR(s)>

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 #1332 (d0b0f67) into sdf14 (d6f68f4) will not change coverage.
The diff coverage is n/a.

❗ Current head d0b0f67 differs from pull request most recent head fa610ed. Consider uploading reports for the commit fa610ed to get more accurate results

@@           Coverage Diff           @@
##            sdf14    #1332   +/-   ##
=======================================
  Coverage   87.49%   87.49%           
=======================================
  Files         134      134           
  Lines       17759    17759           
=======================================
  Hits        15538    15538           
  Misses       2221     2221