fix eval and call return types (#4451)

Author: Akuli

stdlib/3/_tkinter.pyi

@@ -38,8 +38,8 @@ class TclError(Exception): ...
 # Tkapp_UnicodeResult, and it returns a string when it succeeds.
 class TkappType:
     # Please keep in sync with tkinter.Tk
-    def call(self, __command: Union[str, Tuple[Any, ...]], *args: Any) -> str: ...
-    def eval(self, __script: str) -> Any: ...
+    def call(self, __command: Union[str, Tuple[Any, ...]], *args: Any) -> Any: ...
+    def eval(self, __script: str) -> str: ...
     adderrorinfo: Any
     createcommand: Any
     createfilehandler: Any

stdlib/3/tkinter/__init__.pyi

@@ -448,8 +448,8 @@ class Tk(Misc, Wm):
     report_callback_exception: Callable[[Type[BaseException], BaseException, TracebackType], Any]
     # Tk has __getattr__ so that tk_instance.foo falls back to tk_instance.tk.foo
     # Please keep in sync with _tkinter.TkappType
-    call: Callable[..., str]
-    eval: Callable[[str], Any]
+    call: Callable[..., Any]
+    eval: Callable[[str], str]
     adderrorinfo: Any
     createcommand: Any
     createfilehandler: Any