Dispatch independent ctes on compound select
Fix issue in :class:`_sql.CTE` where new :meth:`_sql.HasCTE.add_cte` method
added in version 1.4.21 / :ticket:`6752` failed to function correctly for
"compound select" structures such as :func:`_sql.union`,
:func:`_sql.union_all`, :func:`_sql.except`, etc. Pull request courtesy
Eric Masseran.
Fixes: #6752
Closes: #6849
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/6849
Pull-request-sha:
1c4b4d72b2789cf89ff5043ca964ebdd6c9a6617
Change-Id: I49a16a4fc2af8299502011f3a02d8a2ad93255e3