Update requirements for pytest-postgresql >= 5, Pin moto to < 5
all other swh deps now require pytest-postgresql 5, so do that here too.
moto v5 rejigged the fixtures in a way that's incompatible with swh.objstorage, pin it down for now.
Staging instance, all changes can be removed at any time
all other swh deps now require pytest-postgresql 5, so do that here too.
moto v5 rejigged the fixtures in a way that's incompatible with swh.objstorage, pin it down for now.