Use type hinting generics in standard collections (#19046)

aka PEP 585, added in Python 3.9

 - https://peps.python.org/pep-0585/
 - https://docs.astral.sh/ruff/rules/non-pep585-annotation/

tests/rest/client/sliding_sync/test_extension_thread_subscriptions.py

@@ -13,7 +13,7 @@
 #
 import logging
 from http import HTTPStatus
-from typing import List, Optional, Tuple, cast
+from typing import Optional, cast
 
 from twisted.test.proto_helpers import MemoryReactor
 
@@ -358,7 +358,7 @@ class SlidingSyncThreadSubscriptionsExtensionTestCase(SlidingSyncBase):
         using the companion /thread_subscriptions endpoint.
         """
 
-        thread_root_ids: List[str] = []
+        thread_root_ids: list[str] = []
 
         def make_subscription() -> None:
             thread_root_resp = self.helper.send(
@@ -455,7 +455,7 @@ class SlidingSyncThreadSubscriptionsExtensionTestCase(SlidingSyncBase):
 
     def _do_backpaginate(
         self, *, from_tok: str, to_tok: str, limit: int, access_token: str
-    ) -> Tuple[JsonDict, Optional[str]]:
+    ) -> tuple[JsonDict, Optional[str]]:
         channel = self.make_request(
             "GET",
             "/_matrix/client/unstable/io.element.msc4308/thread_subscriptions"