Fix cachetools decorators (#5690)

Author: JHeilCoveo

stubs/cachetools/cachetools/decorators.pyi

@@ -1,13 +1,13 @@
+from _typeshed import IdentityFunction
 from typing import Any, Callable, ContextManager, MutableMapping, Optional, TypeVar
 
 _KT = TypeVar("_KT")
-_T = TypeVar("_T", bound=Callable[..., Any])
 
 def cached(
     cache: Optional[MutableMapping[_KT, Any]], key: Callable[..., _KT] = ..., lock: Optional[ContextManager[Any]] = ...
-) -> Callable[[_T], _T]: ...
+) -> IdentityFunction: ...
 def cachedmethod(
     cache: Callable[[Any], Optional[MutableMapping[_KT, Any]]],
     key: Callable[..., _KT] = ...,
     lock: Optional[ContextManager[Any]] = ...,
-) -> Callable[[_T], _T]: ...
+) -> IdentityFunction: ...

stubs/cachetools/cachetools/func.pyi

@@ -1,11 +1,11 @@
-from typing import Any, Callable, Optional, Sequence, TypeVar
+from _typeshed import IdentityFunction
+from typing import Callable, Optional, Sequence, TypeVar
 
 _T = TypeVar("_T")
 
-_F = TypeVar("_F", bound=Callable[..., Any])
-_RET = Callable[[_F], _F]
-
-def lfu_cache(maxsize: float = ..., typed: bool = ...) -> _RET[_F]: ...
-def lru_cache(maxsize: float = ..., typed: bool = ...) -> _RET[_F]: ...
-def rr_cache(maxsize: float = ..., choice: Optional[Callable[[Sequence[_T]], _T]] = ..., typed: bool = ...) -> _RET[_F]: ...
-def ttl_cache(maxsize: float = ..., ttl: float = ..., timer: float = ..., typed: bool = ...) -> _RET[_F]: ...
+def lfu_cache(maxsize: float = ..., typed: bool = ...) -> IdentityFunction: ...
+def lru_cache(maxsize: float = ..., typed: bool = ...) -> IdentityFunction: ...
+def rr_cache(
+    maxsize: float = ..., choice: Optional[Callable[[Sequence[_T]], _T]] = ..., typed: bool = ...
+) -> IdentityFunction: ...
+def ttl_cache(maxsize: float = ..., ttl: float = ..., timer: float = ..., typed: bool = ...) -> IdentityFunction: ...