Contributor list workflow does not error when arguments provided in reverse [DBZ-4960]

Migrated from [DBZ-4960](https://issues.redhat.com/browse/DBZ-4960)

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.

Start at the Release Contributors Workflow dispatch entry point and inspect how its two tag arguments are compared by the script. Verify the behavior with the newer tag first, then confirm that using HEAD as the second argument remains valid; done means reversed tags produce an error or meaningful comparison instead of no results.

Written by the indexing model from the issue text.