pandas-devGH-24196: typo fixed

Author: gmaiwald

pandas/tests/groupby/test_groupby.py

@@ -2976,7 +2976,7 @@ def test_groupby_numeric_only_std_no_result(numeric_only):
 def test_groupby_sum_on_nan_should_return_nan(bug_var):
     # GH 24196
     df = pd.DataFrame({
-        'A': [bug_var, bug_var, bug_var, np.nan]
+        "A": [bug_var, bug_var, bug_var, np.nan]
     })
     dfgb = df.groupby(lambda x: x)
     result = dfgb.sum(min_count=1)