Surface container tag cleanup workaround

From https://gitlab.com/gitlab-org/gitlab/-/issues/220886#workaround

doc/administration/packages/container_registry.md

@@ -693,6 +693,35 @@ notifications:
       backoff: 1000
 ```
 
+## Run the Cleanup policy now
+
+To reduce the amount of [Container Registry disk space used by a given project](../troubleshooting/gitlab_rails_cheat_sheet.md#registry-disk-space-usage-by-project),
+administrators can clean up image tags
+and [run garbage collection](#container-registry-garbage-collection).
+
+To remove image tags by running the cleanup policy, run the following commands in the
+[GitLab Rails console](../troubleshooting/navigating_gitlab_via_rails_console.md):
+
+```ruby
+# Numeric ID of the project whose container registry should be cleaned up
+P = <project_id>
+
+# Numeric ID of a developer, maintainer or owner in that project
+U = <user_id>
+
+# Get required details / objects
+user    = User.find_by_id(U)
+project = Project.find_by_id(P)
+repo    = ContainerRepository.find_by(project_id: P)
+policy  = ContainerExpirationPolicy.find_by(project_id: P)
+
+# Start the tag cleanup
+Projects::ContainerRepository::CleanupTagsService.new(project, user, policy.attributes.except("created_at", "updated_at")).execute(repo)
+```
+
+NOTE: **Note:**
+You can also [run cleanup on a schedule](../../user/packages/container_registry/index.md#cleanup-policy).
+
 ## Container Registry garbage collection
 
 NOTE: **Note:**

doc/administration/troubleshooting/gitlab_rails_cheat_sheet.md

@@ -689,10 +689,10 @@ end
 As a GitLab administrator, you may need to reduce disk space consumption.
 A common culprit is Docker Registry images that are no longer in use. To find
 the storage broken down by each project, run the following in the
-GitLab Rails console:
+[GitLab Rails console](../troubleshooting/navigating_gitlab_via_rails_console.md):
 
 ```ruby
-projects_and_size = []
+projects_and_size = [["project_id", "creator_id", "registry_size_bytes", "project path"]]
 # You need to specify the projects that you want to look through. You can get these in any manner.
 projects = Project.last(100)
 
@@ -707,17 +707,21 @@ projects.each do |p|
    end
 
    if project_total_size > 0
-      projects_and_size << [p.full_path,project_total_size]
+      projects_and_size << [p.project_id, p.creator.id, project_total_size, p.full_path]
    end
 end
 
 # projects_and_size is filled out now
 # maybe print it as comma separated output?
 projects_and_size.each do |ps|
-   puts "%s,%s" % ps
+   puts "%s,%s,%s,%s" % ps
 end
 ```
 
+### Run the Cleanup policy now
+
+Find this content in the [Container Registry troubleshooting docs](../packages/container_registry.md#run-the-cleanup-policy-now).
+
 ## Sidekiq
 
 This content has been moved to the [Troubleshooting Sidekiq docs](./sidekiq.md).