Contributor list workflow does not error when arguments provided in reverse

When the Release Contributors Workflow is executed via dispatch & the arguments provided are reversed, meaning that the new tag is provided first rather than the older tag, the script executes but does not return any results.

We should at least ideally see if we can compare the two tags in some meaningful way to be able to assert when they're provided in reverse. We can currently use HEAD in the second argument before we do a release, which is valid. Any comparison we do should continue to allow HEAD as the second argument as valid.