Autogenerate ignores order of columns in an index

[CaselIT]

For the autogenrated the following indexes where considered equal, while in general they aren't

Index('my_index', 'a', 'b')
Index('my_idnex', 'b', 'a')

[sqla-tester]

CaselIT has proposed a fix for this issue in the main branch:

Improved support for expression indexes https://gerrit.sqlalchemy.org/c/sqlalchemy/alembic/+/4426