[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

src/_pytest/runner.py

@@ -213,7 +213,9 @@ def _update_current_test_var(
         # is not atomic or thread-safe, unlike e.g. popping from a builtin dict.
         try:
             os.environ.pop(var_name)
-        except KeyError:  # pragma: no cover # can be removed when #13768 is farther along
+        except (
+            KeyError
+        ):  # pragma: no cover # can be removed when #13768 is farther along
             pass