Add rake task to check db schema is valid
What does this MR do?
Adds CI job to check that db schema after db:migrate:reset is the same one as one in the repository
Are there points in the code the reviewer needs to double check?
no
Why was this MR needed?
There was a case when DB schema was missing an index while migration had it. As result, people who installed GitLab after this migration did not receive an index while people with older instances did.
What are the relevant issue numbers?
Edited by username-removed-444