ci: add Slack webhook notification for new release pipeline

See merge request gitlab-org/container-registry!1094

feat(datastore): use tight timeout for Redis cache operations

See merge request gitlab-org/container-registry!1095

feat(gc): add temporary debug log for deadlocks during manifest deletes

See merge request gitlab-org/container-registry!1098

# [3.54.0](gitlab-org/container-registry@v3.53.0-gitlab...v3.54.0-gitlab) (2022-07-26)

### Features

* **datastore:** use tight timeout for Redis cache operations ([fd675356](gitlab-org/container-registry@fd675356))
* **gc:** add temporary debug log for deadlocks during manifest deletes ([841415b9](gitlab-org/container-registry@841415b9))