This removes all Sidekiq workers tags except for `needs_own_queue`.
Workers tags are documented as short-lived metadata annotations, and are
primarily for use in the GitLab.com deployment. All of the removed tags
are no longer needed:

1. `requires_disk_io` - we added this to workers that accessed shared
   files over NFS when we started migrating Sidekiq away from VMs to
   Kubernetes. These workers no longer use NFS, we just hadn't tidied up
   the tags.
2. `exclude_from_kubernetes` - similarly, in our Kubernetes migration we
   ended up in a state where some workers ran on VMs and others ran on
   Kubernetes, but there was no particular reason for these workers not
   to run on Kubernetes. We didn't remove it earlier because the
   migration was still in progress. This tag was just there to simplify
   the queue selectors, but now that all of Sidekiq on GitLab.com runs
   on Kubernetes, we definitely don't need it.
3. `exclude_from_gitlab_com` - some workers never run on GitLab.com.
   When we were using a queue per worker, there was a small overhead to
   running extra queues, and that overhead added up at GitLab.com's
   scale. Now that we are using [routing rules] to put jobs in far fewer
   queues, we don't need this exclusion any more.

We do want to keep the `needs_own_queue` tag for now, as it applies to
the last point: not every worker can be put in a queue with other
workers, and this annotation helps us keep track of those.

[routing rules]: https://docs.gitlab.com/ee/administration/operations/extra_sidekiq_routing.html