Update the deploy update scripts to optinally take an override hash

As described in this commment, we sometimes need to manually deploy a particular commit for the update responses. My way to make it work is to edit an already existing instance of the script with the new hash, but this is obviously error prone and requires a more fundamental understanding of how it works which not all signers may equally have.

We should perhaps update this script to take an optional override hash as a command-line argument so we can avoid the script edit step.