A maintainer should be able to permanently disable a QA check and/or make it non-fatal

This morning I made an upload with Debusine and I noticed that blhc was failing. That failure was clearly a false positive (that I reported). At the same time, blhc is of low value to this Python arch-all package. I'd like to be able to disable it.

In other cases, for some valid issue that I'd like to temporarily ignore, I might want to make a QA check non-fatal (i.e. it runs, but it doesn't fail the whole workflow).

I guess the principle of least surprise (compared to salsa-ci) would be to let the maintainer provide some configuration knobs in debian/debusine.yml even though the most logical solution in Debusine would be to rely on debusine:task-configuration to override some workflow parameters (although the "allow_failure" knob is not in task_data and thus outside of what we can currently do with task-configuration). But task configuration is a very centralized system with restricted rights due to the very powerful changes that you can perform with it.