bpo-44794: Merge tests for typing.Callable and collection.abc.Callable (GH-27507)

(cherry picked from commit be4cb9089aaf58d5f90da5f9fa66dc3c6763b5a2)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
diff --git a/Lib/_collections_abc.py b/Lib/_collections_abc.py
index bff58ad..33db9b2 100644
--- a/Lib/_collections_abc.py
+++ b/Lib/_collections_abc.py
@@ -478,8 +478,7 @@ def __getitem__(self, item):
         # then X[int, str] == X[[int, str]].
         param_len = len(self.__parameters__)
         if param_len == 0:
-            raise TypeError(f'There are no type or parameter specification'
-                            f'variables left in {self}')
+            raise TypeError(f'{self} is not a generic class')
         if (param_len == 1
                 and isinstance(item, (tuple, list))
                 and len(item) > 1) or not isinstance(item, tuple):