What does this MR do?
This fixes a reported problem with a migration (see #37361 (closed)). When upgrading from previous versions, we seem to have cases where two indexes are present on
Multiple indexes found on snippets columns [:project_id]. Specify an index name from index_snippets_on_project_id, snippets_project_id_idx
index_snippets_on_project_id is the one we were wanting to drop. This is now made explicit in the migration and should be included in the next patch release for 12.5.