Remove log counts from container registry cleanup worker

What does this MR do and why?

In #382513 (closed) we have created a new Grafana dashboard that allows us to monitor the row count of some tables/conditions related to the Container Registry. As result, we no longer need to execute these row count queries and log them on the ContainerRegistry::CleanupWorker. This MR removes them.

Marked as draft to prevent merging until Add dashboard for registry metrics on the Rails... (gitlab-com/runbooks!5994 - merged) is merged.

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