mypy: Fix types for redis.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

zerver/management/commands/check_redis.py

@@ -21,7 +21,7 @@ class Command(BaseCommand):
                             help="Actually trim excess")
 
     def _check_within_range(self, key: str, count_func: Callable[[], int],
-                            trim_func: Optional[Callable[[str, int], None]]=None) -> None:
+                            trim_func: Optional[Callable[[str, int], object]]=None) -> None:
         user_id = int(key.split(':')[1])
         user = get_user_profile_by_id(user_id)
         entity = RateLimitedUser(user)
@@ -48,7 +48,7 @@ than max_api_calls! (trying to trim) %s %s", key, count)
         wildcard_zset = "ratelimit:*:*:zset"
 
         trim_func: Optional[
-            Callable[[str, int], None]
+            Callable[[str, int], object]
         ] = lambda key, max_calls: client.ltrim(key, 0, max_calls - 1)
         if not options['trim']:
             trim_func = None

zerver/migrations/0260_missed_message_addresses_from_redis_to_db.py

@@ -28,16 +28,14 @@ def move_missed_message_addresses_to_database(apps: StateApps, schema_editor: Da
             redis_client.delete(key)
             continue
 
-        result = redis_client.hmget(key, 'user_profile_id', 'recipient_id', 'subject')
-        if not all(val is not None for val in result):
+        user_profile_id, recipient_id, subject_b = redis_client.hmget(
+            key, 'user_profile_id', 'recipient_id', 'subject'
+        )
+        if user_profile_id is None or recipient_id is None or subject_b is None:
             # Missing data, skip this key; this should never happen
             redis_client.delete(key)
             continue
 
-        user_profile_id: bytes
-        recipient_id: bytes
-        subject_id: bytes
-        user_profile_id, recipient_id, subject_b = result
         topic_name = subject_b.decode('utf-8')
 
         # The data model for missed-message emails has changed in two