Increase replica count limit for urgent cpu bound shard

What does this MR do?

After some previous MRs to tune the concurrency, this just outright grows our upper HPA limit for this set of worker replicas.

Author Check-list

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• Check if all of the following apply:
  • Assign to the correct reviewer per the contributing document
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  • Link to related MRs for applying the changes on other environments
  • Link to related Chef changes
  • If necessary link to a Criticality 4 Change Request issue

Reviewer Check-list

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  • Reviewed the diff jobs to confirm changes are as expected
  • No changes shown in the diffs not associated with this MR - This may require a rebase or further investigation

Applier Check-list

• Make sure there is no ongoing deployment for the affected envs before merging (see #announcements slack channel)