Adjust `retention-days` option for forensic purposes

The default value for the following option is 90 days. Setting the option to a value of 1 doesn't help anything, so let's remove it.

https://github.com/irods/irods_reusable_github_workflows/blob/b6b04ce7ff3c8164eadb97345dd1abba005393dc/.github/workflows/build-and-test-plugin-ubuntu.yml#L106