Add missing type hints to synapse.logging.context (#11556)

stubs/txredisapi.pyi

@@ -17,11 +17,12 @@
 from typing import Any, List, Optional, Type, Union
 
 from twisted.internet import protocol
+from twisted.internet.defer import Deferred
 
 class RedisProtocol(protocol.Protocol):
     def publish(self, channel: str, message: bytes): ...
-    async def ping(self) -> None: ...
-    async def set(
+    def ping(self) -> "Deferred[None]": ...
+    def set(
         self,
         key: str,
         value: Any,
@@ -29,8 +30,8 @@ class RedisProtocol(protocol.Protocol):
         pexpire: Optional[int] = None,
         only_if_not_exists: bool = False,
         only_if_exists: bool = False,
-    ) -> None: ...
-    async def get(self, key: str) -> Any: ...
+    ) -> "Deferred[None]": ...
+    def get(self, key: str) -> "Deferred[Any]": ...
 
 class SubscriberProtocol(RedisProtocol):
     def __init__(self, *args, **kwargs): ...