Prepare release 14.4.0

[j-rivero]

🎈 Release

Preparation for 14.4.0 release.

Comparison to 14.3.0: https://github.com/gazebosim/sdformat/compare/sdformat14_14.3.0...sdf14

Checklist

• [x] 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.

[bperseghetti]

Needs package.yaml version bump I think.

[iche033]

@j-rivero I'll merge this and trigger the release