Improve stubs for classmethod and staticmethod (#10421)

Author: AlexWaygood

stdlib/abc.pyi

@@ -31,7 +31,7 @@ def abstractmethod(funcobj: _FuncT) -> _FuncT: ...
 
 class abstractclassmethod(classmethod[_T, _P, _R_co]):
     __isabstractmethod__: Literal[True]
-    def __init__(self, callable: Callable[Concatenate[_T, _P], _R_co]) -> None: ...
+    def __init__(self, callable: Callable[Concatenate[type[_T], _P], _R_co]) -> None: ...
 
 class abstractstaticmethod(staticmethod[_P, _R_co]):
     __isabstractmethod__: Literal[True]

stdlib/builtins.pyi

@@ -132,6 +132,9 @@ class staticmethod(Generic[_P, _R_co]):
     @property
     def __isabstractmethod__(self) -> bool: ...
     def __init__(self, __f: Callable[_P, _R_co]) -> None: ...
+    @overload
+    def __get__(self, __instance: None, __owner: type) -> Callable[_P, _R_co]: ...
+    @overload
     def __get__(self, __instance: _T, __owner: type[_T] | None = None) -> Callable[_P, _R_co]: ...
     if sys.version_info >= (3, 10):
         __name__: str
@@ -142,16 +145,19 @@ class staticmethod(Generic[_P, _R_co]):
 
 class classmethod(Generic[_T, _P, _R_co]):
     @property
-    def __func__(self) -> Callable[Concatenate[_T, _P], _R_co]: ...
+    def __func__(self) -> Callable[Concatenate[type[_T], _P], _R_co]: ...
     @property
     def __isabstractmethod__(self) -> bool: ...
-    def __init__(self, __f: Callable[Concatenate[_T, _P], _R_co]) -> None: ...
+    def __init__(self, __f: Callable[Concatenate[type[_T], _P], _R_co]) -> None: ...
+    @overload
     def __get__(self, __instance: _T, __owner: type[_T] | None = None) -> Callable[_P, _R_co]: ...
+    @overload
+    def __get__(self, __instance: None, __owner: type[_T]) -> Callable[_P, _R_co]: ...
     if sys.version_info >= (3, 10):
         __name__: str
         __qualname__: str
         @property
-        def __wrapped__(self) -> Callable[Concatenate[_T, _P], _R_co]: ...
+        def __wrapped__(self) -> Callable[Concatenate[type[_T], _P], _R_co]: ...
 
 class type:
     @property