Improve type hints for cached decorator. (#15658)

The cached decorators always return a Deferred, which was not
properly propagated. It was close enough when wrapping coroutines,
but failed if a bare function was wrapped.

1 files changed, 1 insertions, 1 deletions

diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py

index e068f27a10..ae9c201b87 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -1099,7 +1099,7 @@ class RoomMemberWorkerStore(EventsWorkerStore, CacheInvalidationWorkerStore):
         # `get_joined_hosts` is called with the "current" state group for the
         # room, and so consecutive calls will be for consecutive state groups
         # which point to the previous state group.
-        cache = await self._get_joined_hosts_cache(room_id)  # type: ignore[misc]
+        cache = await self._get_joined_hosts_cache(room_id)
 
         # If the state group in the cache matches, we already have the data we need.
         if state_entry.state_group == cache.state_group: