Add missing await to sleep calls (#18763)

changelog.d/18763.bugfix

@@ -0,0 +1 @@
+Fix an issue that could cause logcontexts to be lost on rate-limited requests. Found by @realtyem.

synapse/http/server.py

@@ -337,7 +337,7 @@ class _AsyncResource(resource.Resource, metaclass=abc.ABCMeta):
                     callback_return = await self._async_render(request)
                 except LimitExceededError as e:
                     if e.pause:
-                        self._clock.sleep(e.pause)
+                        await self._clock.sleep(e.pause)
                     raise
 
                 if callback_return is not None:

synapse/storage/databases/main/deviceinbox.py

@@ -1031,7 +1031,7 @@ class DeviceInboxWorkerStore(SQLBaseStore):
 
             # We sleep a bit so that we don't hammer the database in a tight
             # loop first time we run this.
-            self._clock.sleep(1)
+            await self._clock.sleep(1)
 
     async def get_devices_with_messages(
         self, user_id: str, device_ids: StrCollection