script checks: Update needs to update Alloc as well

[tgross]

Without updating the alloc during the Update hook, we won't change any values in the script check and the check IDs will mismatch between the script runner and Consul.

[github-actions]

I'm going to lock this pull request because it has been closed for 120 days ⏳. This helps our maintainers find and focus on the active contributions.
If you have found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.