Only import collections.abc in doctests.

Author: jaraco

importlib_metadata/__init__.py

@@ -11,7 +11,7 @@
 import functools
 import itertools
 import posixpath
-import collections.abc
+import collections
 
 from ._compat import (
     NullFinder,
@@ -841,6 +841,7 @@ def packages_distributions() -> Mapping[str, List[str]]:
     Return a mapping of top-level packages to their
     distributions.
 
+    >>> import collections.abc
     >>> pkgs = packages_distributions()
     >>> all(isinstance(dist, collections.abc.Sequence) for dist in pkgs.values())
     True