Remove 'compat' hook for importlib_metadata.

src/flake8/_compat.py

@@ -6,9 +6,4 @@ if sys.version_info >= (3,):  # pragma: no cover (PY3+)
 else:  # pragma: no cover (<PY3)
     from functools32 import lru_cache
 
-if False:  # pragma: no cover (PY??+)
-    import importlib.metadata as importlib_metadata
-else:  # pragma: no cover (<PY??)
-    import importlib_metadata
-
-__all__ = ("lru_cache", "importlib_metadata")
+__all__ = ("lru_cache",)

src/flake8/plugins/manager.py

@@ -2,9 +2,10 @@
 import logging
 from typing import Any, Dict, List, Optional, Set
 
+import importlib_metadata
+
 from flake8 import exceptions
 from flake8 import utils
-from flake8._compat import importlib_metadata
 
 LOG = logging.getLogger(__name__)
 

tests/integration/test_checker.py

@@ -1,9 +1,9 @@
 """Integration tests for the checker submodule."""
 import mock
 import pytest
+import importlib_metadata
 
 from flake8 import checker
-from flake8._compat import importlib_metadata
 from flake8.plugins import manager
 from flake8.processor import FileProcessor
 

tests/unit/test_plugin_manager.py

@@ -1,7 +1,7 @@
 """Tests for flake8.plugins.manager.PluginManager."""
 import mock
+import importlib_metadata
 
-from flake8._compat import importlib_metadata
 from flake8.plugins import manager