Import artifacts update completed and logic simplified

Closes #415 (closed)

Successful pipeline run:

• https://code-ib-mario.staging.dso.mil/dsop/redhat/ubi/ubi8/-/jobs/23555 (https and docker download working)
• https://code-ib-mario.staging.dso.mil/dsop/redhat/ubi/ubi8/-/jobs/23574#L45 (deprecated message shows correctly)
• https://code-ib-mario.staging.dso.mil/dsop/redhat/ubi/ubi8/-/jobs/23705 (new github url attempting to grab github auth)

Unable to test github and docker auth cases in staging, but default is working and key retrieval hasn't changed.