Proposal: Delete bugfix PR label

[AprilSylph]

Now that we're starting to use conventional commits/PR titles, the bugfix label seems obsolete to me.

Non-collaborators can't apply labels to their own issues/PRs anyway, so I'm in favour of deleting it for the sake of both simplicity and equality.

@marcustyphoon do you have any reasons to keep it around?

[marcustyphoon]

Nope, agreed!