Explicitly set ARG UBI_IMAGE

Upstream Dockerfiles no longer set ARG UBI_IMAGE, so explictly set them to point to RedHat minimal UBI image.

Explicitly set ARG UBI_IMAGE
82c79b5b · Andrew Patterson · 73590ae3 · 82c79b5b
Verified Commit 82c79b5b authored 2 months ago by Andrew Patterson
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,7 +5,7 @@ ARG BASE_TAG=17.7.0
 ARG UBI_TAG=9.5

 ARG RUBY_IMAGE=${BASE_REGISTRY}/gitlab/gitlab/gitlab-ruby:${BASE_TAG}
-ARG UBI_IMAGE=
+ARG UBI_IMAGE=${BASE_REGISTRY}/redhat/ubi/ubi9-minimal:${UBI_TAG}

 FROM ${RUBY_IMAGE} as target