Filter by gitlab_schema when displaying batched background migrations

Context:

when listing migrations for each database we use the relevant connection, but do. not filter by gitlab_schema which makes migrations that were created before the split and existing in both databases being listed. They are not executed for each database though, as workers do filter by gitlab_schema, so it’s just a problem with the list view. At least this is what I think is happening.

By @krasio

slack thread: https://gitlab.slack.com/archives/CNZ8E900G/p1657167601675329?thread_ts=1657165560.540149&cid=CNZ8E900G

Solution: Filter by gitlab_schema when displaying batched background migrations in the admin panel