this is a backport from
nm-1-42 for ignore-carrier handling of bonds.
Currently, the branch contains a lot of patches (but not all, for example the devcon handling for autoconnect blocking). By taking them all, the cherry-pick apply mostly without merge conflicts (some adjustments are necessary).
Maybe a smaller set of patches could and should be found for the stable branch. First, I want to see CI passing, before shrinking it down further.