typing: Use accurate type hints for dictionaries.

This fixes the mypy errors related to dictionaries with django-stubs.

analytics/lib/counts.py

@@ -302,7 +302,7 @@ def do_increment_logging_stat(
     table = stat.data_collector.output_table
     if table == RealmCount:
         assert isinstance(zerver_object, Realm)
-        id_args = {"realm": zerver_object}
+        id_args: Dict[str, Union[Realm, UserProfile, Stream]] = {"realm": zerver_object}
     elif table == UserCount:
         assert isinstance(zerver_object, UserProfile)
         id_args = {"realm": zerver_object.realm, "user": zerver_object}

corporate/lib/stripe.py

@@ -5,7 +5,7 @@ import secrets
 from datetime import datetime, timedelta
 from decimal import Decimal
 from functools import wraps
-from typing import Any, Callable, Dict, Generator, Optional, Tuple, TypeVar, cast
+from typing import Any, Callable, Dict, Generator, Optional, Tuple, TypeVar, Union, cast
 
 import orjson
 import stripe
@@ -1032,7 +1032,7 @@ def downgrade_small_realms_behind_on_payments_as_needed() -> None:
 
             downgrade_now_without_creating_additional_invoices(realm)
             void_all_open_invoices(realm)
-            context: Dict[str, str] = {
+            context: Dict[str, Union[str, Realm]] = {
                 "upgrade_url": f"{realm.uri}{reverse('initial_upgrade')}",
                 "realm": realm,
             }

zerver/lib/cache_helpers.py

@@ -1,7 +1,7 @@
 # See https://zulip.readthedocs.io/en/latest/subsystems/caching.html for docs
 import datetime
 import logging
-from typing import Any, Callable, Dict, List, Tuple
+from typing import Any, Callable, Dict, Iterable, List, Tuple
 
 from django.conf import settings
 from django.contrib.sessions.models import Session
@@ -106,7 +106,7 @@ def get_users() -> List[UserProfile]:
 # wrapper the below adds an extra 3ms or so to startup time for
 # anything importing this file).
 cache_fillers: Dict[
-    str, Tuple[Callable[[], List[Any]], Callable[[Dict[str, Any], Any], None], int, int]
+    str, Tuple[Callable[[], Iterable[Any]], Callable[[Dict[str, Any], Any], None], int, int]
 ] = {
     "user": (get_users, user_cache_items, 3600 * 24 * 7, 10000),
     "client": (