Comment 3 for bug 1999159

Per the breakdown and alaysis of my comment #1 above:

  The only differences in debhelper-compate script changes we are seeing across the downgrade of debhelper-compat 10 to debhelper-compat 9:

   1. The removal errant try-restart <all cloud-init services>
       -- -which we need to drop and was the intent of this bug/fix
   2. Migration of identical dh_python3 section is a little earlier
      -- no risk change, same content in a different part of the file
   3.bookend comments and escaping of ~ in rm_conffiles
      -- were working in both compat 10 and compat 9 version of our postinst postrm prerm scripts.

Additionally, the intent of this changeset is also to revert to the previous debhelper compat state that was already present and fully functional in cloud-init prior to 22.3-13. So the way this will continue to behave was reasonable for years prior to this change. Our only risk would be in the downgrade from compat level 10 to compat level 9 and the diffs we see in control files don't indicate risk there.