…p for user

Spawning from #17187

Before:
```
$ SYNAPSE_POSTGRES=1 SYNAPSE_POSTGRES_USER=postgres SYNAPSE_TEST_LOG_LEVEL=INFO poetry run trial tests.replication.storage.test_events
[...]
Traceback (most recent call last):
  File "pypoetry/virtualenvs/matrix-synapse-xCtC9ulO-py3.12/lib/python3.12/site-packages/twisted/trial/runner.py", line 711, in loadByName
    return self.suiteFactory([self.findByName(name, recurse=recurse)])
  File "pypoetry/virtualenvs/matrix-synapse-xCtC9ulO-py3.12/lib/python3.12/site-packages/twisted/trial/runner.py", line 474, in findByName
    obj = reflect.namedModule(searchName)
  File "pypoetry/virtualenvs/matrix-synapse-xCtC9ulO-py3.12/lib/python3.12/site-packages/twisted/python/reflect.py", line 156, in namedModule
    topLevel = __import__(name)
  File "synapse/tests/replication/storage/test_events.py", line 33, in <module>
    from synapse.handlers.room import RoomEventSource
  File "synapse/synapse/handlers/room.py", line 74, in <module>
    from synapse.rest.admin._base import assert_user_is_admin
  File "synapse/synapse/rest/__init__.py", line 24, in <module>
    from synapse.rest import admin
  File "synapse/synapse/rest/admin/__init__.py", line 41, in <module>
    from synapse.handlers.pagination import PURGE_HISTORY_ACTION_NAME
  File "synapse/synapse/handlers/pagination.py", line 30, in <module>
    from synapse.handlers.room import ShutdownRoomParams, ShutdownRoomResponse
builtins.ImportError: cannot import name 'ShutdownRoomParams' from partially initialized module 'synapse.handlers.room' (most likely due to a circular import) (synapse/synapse/handlers/room.py)
```

Co-authored-by: Erik Johnston <erikj@element.io>