Revert "Remove importlib-metadata and importlib-resources"

This reverts commit 38435ae81c.

lib/importlib_resources/tests/_compat.py

@@ -0,0 +1,32 @@
+import os
+
+
+try:
+    from test.support import import_helper  # type: ignore
+except ImportError:
+    # Python 3.9 and earlier
+    class import_helper:  # type: ignore
+        from test.support import (
+            modules_setup,
+            modules_cleanup,
+            DirsOnSysPath,
+            CleanImport,
+        )
+
+
+try:
+    from test.support import os_helper  # type: ignore
+except ImportError:
+    # Python 3.9 compat
+    class os_helper:  # type:ignore
+        from test.support import temp_dir
+
+
+try:
+    # Python 3.10
+    from test.support.os_helper import unlink
+except ImportError:
+    from test.support import unlink as _unlink
+
+    def unlink(target):
+        return _unlink(os.fspath(target))