Use TYPE_CHECKING (#6771)

src/_pytest/config/__init__.py

@@ -795,7 +795,7 @@ class Config:
             kwargs=dict(parser=self._parser, pluginmanager=self.pluginmanager)
         )
 
-        if False:  # TYPE_CHECKING
+        if TYPE_CHECKING:
             from _pytest.cacheprovider import Cache
 
             self.cache = None  # type: Optional[Cache]

testing/test_runner.py

@@ -13,10 +13,11 @@ import pytest
 from _pytest import outcomes
 from _pytest import reports
 from _pytest import runner
+from _pytest.compat import TYPE_CHECKING
 from _pytest.config import ExitCode
 from _pytest.outcomes import OutcomeException
 
-if False:  # TYPE_CHECKING
+if TYPE_CHECKING:
     from typing import Type