This is same change as
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/64577, which had
to be reverted and rescheduled for 14.2.

1. Ensure the migration of `event_id` to `event_id_convert_to_bigint` is
completed.
2. Copy indexes and FKs
3. Swap columns

See https://gitlab.com/gitlab-org/gitlab/-/issues/288005.

Changelog: other