Apply suggestions from code review

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

synapse/push/push_rule_evaluator.py

@@ -187,7 +187,7 @@ class PushRuleEvaluatorForEvent:
 # Caches (string, is_glob, word_boundary) -> regex for push. See _glob_matches
 regex_cache = LruCache(
     50000, "regex_push_cache"
-)  # type: LruCache[Tuple[str, bool, bool],Pattern]
+)  # type: LruCache[Tuple[str, bool, bool], Pattern]
 
 
 def _glob_matches(glob: str, value: str, word_boundary: bool = False) -> bool:

synapse/util/caches/lrucache.py

@@ -283,7 +283,7 @@ class LruCache(Generic[KT, VT]):
                 return value
 
         @overload
-        def cache_pop(key: KT, default: Literal[None] = None) -> Union[None, VT]:
+        def cache_pop(key: KT, default: Literal[None] = None) -> Optional[VT]:
             ...
 
         @overload