Revert "TST: groupby apply with indexing and colunm aggregation returns the column (pandas-dev#7002)"

This reverts commit 2e77cef.

Author: fangchenli

pandas/tests/groupby/test_apply.py

@@ -961,13 +961,3 @@ def fn(x):
         name="col2",
     )
     tm.assert_series_equal(result, expected)
-
-
-def test_apply_function_with_indexing_return_column():
-    # GH: 7002
-    df = DataFrame({'foo1': ['one', 'two', 'two', 'three', 'one', 'two'],
-                    'foo2': np.random.randn(6)})
-    result = df.groupby('foo1', as_index=False).apply(lambda x: x.mean())
-    expected = df.groupby('foo1', as_index=False).mean()
-    tm.assert_frame_equal(result, expected)
-    assert 'foo1' in result.columns