Update package maintainers (backport #1203)

[mergify]

This commit updates the package maintainers as the project's governance has changed a bit.

---

This is an automatic backport of pull request #1203 done by Mergify.

[mergify]

Cherry-pick of 0f80235 has failed:

On branch mergify/bp/humble/pr-1203
Your branch is up to date with 'origin/humble'.

You are currently cherry-picking commit 0f80235.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   ur/package.xml
	both modified:   ur_calibration/package.xml
	both modified:   ur_controllers/package.xml
	both modified:   ur_dashboard_msgs/package.xml
	both modified:   ur_moveit_config/package.xml
	both modified:   ur_robot_driver/package.xml

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally