Merge branch 'backfill-desired-sharding-key-small-table-step3-deployment_approvals' into 'master'

Add NOT NULL for sharding key on deployment_approvals

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/161603



Merged-by: Tiger Watson <twatson@gitlab.com>
Approved-by: Tiger Watson <twatson@gitlab.com>
Co-authored-by: Manoj M J <mmj@gitlab.com>