Preparing for Melodic sync 2021-12-17

We’re getting ready for the last Melodic sync of the year.

Melodic currently has 2 regressions and 84 packages ready to sync.

I have a revert PR open to fix the regressions: Revert "toposens: 2.3.1-1 in 'melodict/distribution.yaml' (#31186)" by clalancette · Pull Request #31508 · ros/rosdistro · GitHub

I’m going to start holding Melodic packages as of today, December 17, and plan to do a sync next week.

Please reply here if there are any other outstanding issues I should know about before performing a sync.

The sync is out.