Add sharding keys for feature category container_registry

These tables have been identified as [cell local tables](https://docs.gitlab.com/ee/development/database/multiple_databases.html#guidelines-on-choosing-between-gitlab_main_cell-and-gitlab_main_clusterwide-schema).

All cell local tables require a [sharding key](https://docs.gitlab.com/ee/development/database/multiple_databases.html#defining-a-sharding-key-for-all-cell-local-tables).

A sharding key has been automatically selected for these tables. The sharding key was chosen because it is a
`NOT NULL` column referencing either `projects` or `namespaces`.

Please confirm that this table should indeed be cell local, and that the selected column is an appropriate
sharding key.

If you have any questions or concerns, reach out to @tigerwnz or @DylanGriffith.

This merge request was created using the
[gitlab-housekeeper](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/139492)
gem.

/assign_reviewer @jaime

This commit was generated by
[gitlab-housekeeper](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/139492).

Changelog: other