TST: Add test for GroupBy.describe() with duplicate columns #35423
Description
-
I have checked that this issue has not already been reported.
-
I have confirmed this bug exists on the latest version of pandas.
-
(optional) I have confirmed this bug exists on the master branch of pandas.
While working on #35314 I made a change that broke GroupBy.apply if you called it on a DataFrame with duplicate columns; however, this break as not caught by any test. Was just caught on inpsection: #35314 (comment)
This issue is just to add a test for this case to ensure it works and doesn't break again in the future.