Add version check to CLAW update [v8]

[gururajsh]

Description of the Change

Before updating CLAW with new release version, make sure the new version is not already present in the list. If the new version already exists, then something has gone wrong with the release process, so it exits.

Why Is This PR Valuable?

Prevents duplicate entries to CLAW.

Applicable Issues

List any applicable GitHub Issues here

How Urgent Is The Change?

Is the change urgent? If so, explain why it is time-sensitive.

Other Relevant Parties

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