Add Python 3.10 support to _distutils_hack

Get the 'Loader' abstract class from importlib.abc rather than
importlib.util.abc (alias removed in Python 3.10).

_distutils_hack/__init__.py

@@ -74,9 +74,10 @@ class DistutilsMetaFinder:
         return method()
 
     def spec_for_distutils(self):
+        import importlib.abc
         import importlib.util
 
-        class DistutilsLoader(importlib.util.abc.Loader):
+        class DistutilsLoader(importlib.abc.Loader):
 
             def create_module(self, spec):
                 return importlib.import_module('._distutils', 'setuptools')

changelog.d/2361.change.rst

+Add Python 3.10 support to _distutils_hack. Get the 'Loader' abstract class
+from importlib.abc rather than importlib.util.abc (alias removed in Python
+3.10).