delete messages from device_inbox table when deleting device

changelog.d/10098.bugfix

@@ -0,0 +1 @@
+Fix a bug where messages in `device_inbox` table where not deleted, when deleting device(s).

synapse/storage/databases/main/devices.py

@@ -1133,6 +1133,12 @@ async def delete_device(self, user_id: str, device_id: str) -> None:
             desc="delete_device",
         )
 
+        await self.db_pool.simple_delete_many(
+            table="device_inbox",
+            keyvalues={"user_id": user_id, "device_id": device_id},
+            desc="delete_device",
+        )
+
         self.device_id_exists_cache.invalidate((user_id, device_id))
 
     async def delete_devices(self, user_id: str, device_ids: List[str]) -> None:
@@ -1149,6 +1155,15 @@ async def delete_devices(self, user_id: str, device_ids: List[str]) -> None:
             keyvalues={"user_id": user_id, "hidden": False},
             desc="delete_devices",
         )
+
+        await self.db_pool.simple_delete_many(
+            table="device_inbox",
+            column="device_id",
+            iterable=device_ids,
+            keyvalues={"user_id": user_id},
+            desc="delete_devices",
+        )
+
         for device_id in device_ids:
             self.device_id_exists_cache.invalidate((user_id, device_id))