Remove SelectableGroups deprecation exception for flake8.

CHANGES.rst

@@ -1,3 +1,9 @@
+v4.5.0
+=======
+
+* #319: Remove ``SelectableGroups`` deprecation exception
+  for flake8.
+
 v4.4.0
 =======
 

importlib_metadata/__init__.py

@@ -367,14 +367,6 @@ def _parse_groups(text):
         )
 
 
-def flake8_bypass(func):
-    # defer inspect import as performance optimization.
-    import inspect
-
-    is_flake8 = any('flake8' in str(frame.filename) for frame in inspect.stack()[:5])
-    return func if not is_flake8 else lambda: None
-
-
 class Deprecated:
     """
     Compatibility add-in for mapping to indicate that
@@ -410,7 +402,7 @@ def __getitem__(self, name):
         return super().__getitem__(name)
 
     def get(self, name, default=None):
-        flake8_bypass(self._warn)()
+        self._warn()
         return super().get(name, default)
 
     def __iter__(self):

pytest.ini

@@ -5,3 +5,5 @@ doctest_optionflags=ALLOW_UNICODE ELLIPSIS
 # workaround for warning pytest-dev/pytest#6178
 junit_family=xunit2
 filterwarnings=
+	# Suppress deprecation warning in flake8
+	ignore:SelectableGroups dict interface is deprecated::flake8