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

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

Author: pre-commit-ci[bot]

tests/func/experiments/test_remove.py

@@ -252,6 +252,6 @@ def test_keep_selected_by_rev(
     for exp in expected_removed:
         assert scm.get_ref(str(refs[exp])) is None
 
-    for exp in refs.keys():
+    for exp in refs:
         if exp not in expected_removed:
             assert scm.get_ref(str(refs[exp])) is not None