[Development] [FYI] staging to 5.3 now restricted

[Oswald Buddenhagen]

moin,

to prevent wasting a whole integration cycle on each change in 5.3, i
now locked down staging. please add me as a reviewer when your change
gets approved, and i'll do integration batches every few days (depending
on demand).

you still should fix sufficiently severe issues in 5.3, and the branch
continues to be forward-merged, but at this point it really makes sense
to target 5.4 in most cases.