RHEL8 - cannot install due to mismatch between versions

From @vazovn

> Setting the `__postgresql_version_dotless: ""` seems to do the fix. The good news is that one can do this in the ansible playbook yaml file and thus not affect the role. Yet, if in the future postgresql releases the digits (postresqlXX) reappear again, this fix will be a problem.
>
> fatal: [galaxy01-test.educloud.no]: FAILED! => {"changed": false, "failures": ["No package pgdg-redhat-repo available."], "msg": "Failed to install some of the specified packages", "rc": 1, "results": []}

We should write some molecule tests for this role