feat: specify oc version in openshift deployer

[DerekRoberts]

Cronjobs are having problems with GitHub current oc version, 4.15. We're using 4.13. Manually adjusting versions fixes it. Rather than having to worry about that in workflows, add a flag for oc_version to the deployer.

This works:

  cronjob:
    name: Cronjob
    # needs: [deploys]
    env:
      JOB: ${{ github.event.repository.name }}-${{ github.event.number }}-sync    
      OC: https://mirror.openshift.com/pub/openshift-v4/clients/ocp/stable-4.13/openshift-client-linux.tar.gz
    runs-on: ubuntu-latest
    steps:
      - name: Cronjob
        run: |
          wget ${{ env.OC }} -qO - | tar -xzvf - oc
          ./oc version
          ./oc login --token=${{ secrets.OC_TOKEN }} --server=${{ vars.OC_SERVER }}
          ./oc project ${{ secrets.OC_NAMESPACE }} # Safeguard!
          ./oc create job ${{ env.JOB }}-${{ github.run_number }} --from=cronjob/${{ env.JOB }}
          sleep 10
          ./oc logs -l job-name=${{ env.JOB }}-${{ github.run_number }} --tail=400 --follow