gh-104328: Fix typo in typing.Generic multiple inheritance error message (#104335)

Author: Eclips4

Lib/typing.py

@@ -1896,7 +1896,7 @@ def __init_subclass__(cls, *args, **kwargs):
                         base.__origin__ is Generic):
                     if gvars is not None:
                         raise TypeError(
-                            "Cannot inherit from Generic[...] multiple types.")
+                            "Cannot inherit from Generic[...] multiple times.")
                     gvars = base.__parameters__
             if gvars is not None:
                 tvarset = set(tvars)