build for ppc64le architecture via gitlab ci

- automatically build and deploy gitlab helper image
- create debian package for ppc64el
2 jobs for ppc64le in 2 minutes and 52 seconds (queued for 6 seconds)
Status Name Job ID Coverage
  Build
passed build-ppc64le #20863

00:02:51

passed helper-image-ppc64le #20864
ppc64le

00:02:24