ci-package-builder: Make most jobs interruptible and skip redundant pipelines

This is quite important on upstream branches such as debian/bullseye or proposed-updates/* branches where we end up pushing to from pipelines running on the same branch.

For instance, running a pipeline on debian/bullseye pulls updates and lands them to debian/bullseye itself, which causes the same pipeline to run again, this time without pulling new updates.

On proposed-updates/* branches the scan-licenses may end up updating the branch itself when updating the copyright information.

By setting interruptible:true we minimize the duplication in the cases described above.

However, mark tag-release and upload as not interruptible to avoid incomplete pushes and uploads from there.