Add new v2 approval rule associations to security policies for new approval rule architecture. Update the associations for v2 approval rules accordingly. The table will need to have a defined sharding key similar to https://gitlab.com/gitlab-org/gitlab/-/merge_requests/179861. For reference consult the new architecture in the [Architecture Design Document](https://handbook.gitlab.com/handbook/engineering/architecture/design-documents/rearchitect_approval_rules/) and the tables which were created in https://gitlab.com/gitlab-org/gitlab/-/merge_requests/171114+ and https://gitlab.com/gitlab-org/gitlab/-/merge_requests/174517+.