Make SLES branch builds pull image from dev registry only

Signed-off-by: Balasankar "Balu" C <balasankar@gitlab.com>

.gitlab-ci.yml

@@ -39,6 +39,8 @@ variables:
   # settings of omnibus-gitlab mirror in dev.gitlab.org so that builds there
   # will use images from that registry and not depend on GitLab.com
   BUILDER_IMAGE_REGISTRY: "registry.gitlab.com/gitlab-org/gitlab-omnibus-builder"
+  # To be used for images that exist only on dev.gitlab.org
+  DEV_BUILDER_IMAGE_REGISTRY: 'dev.gitlab.org:5005/cookbooks/gitlab-omnibus-builder'
   PUBLIC_BUILDER_IMAGE_REGISTRY: "registry.gitlab.com/gitlab-org/gitlab-omnibus-builder"
   BUILDER_IMAGE_REVISION: "4.9.1"
   # The registry to pull the assets image from

gitlab-ci-config/dev-gitlab-org.yml

@@ -351,14 +351,18 @@ AmazonLinux-2022-arm64-branch:
   tags:
   - docker-arm-builder
 SLES-12.5-branch:
-  image: "${BUILDER_IMAGE_REGISTRY}/sles_12sp5:${BUILDER_IMAGE_REVISION}"
+  image: "${DEV_BUILDER_IMAGE_REGISTRY}/sles_12sp5:${BUILDER_IMAGE_REVISION}"
   extends: .branch_template
+  variables:
+    DOCKER_AUTH_CONFIG: $DEV_BUILDER_DOCKER_AUTH_CONFIG
   rules:
     - !reference [.default_rules, rules]
     - if: '$PIPELINE_TYPE =~ /EE_(NIGHTLY|BRANCH)_BUILD_PIPELINE$/'
 SLES-15.2-branch:
-  image: "${BUILDER_IMAGE_REGISTRY}/sles_15sp2:${BUILDER_IMAGE_REVISION}"
+  image: "${DEV_BUILDER_IMAGE_REGISTRY}/sles_15sp2:${BUILDER_IMAGE_REVISION}"
   extends: .branch_template
+  variables:
+    DOCKER_AUTH_CONFIG: $DEV_BUILDER_DOCKER_AUTH_CONFIG
   rules:
     - !reference [.default_rules, rules]
     - if: '$PIPELINE_TYPE =~ /EE_(NIGHTLY|BRANCH)_BUILD_PIPELINE$/'

gitlab-ci-config/gitlab-com.yml

@@ -735,7 +735,7 @@ pages:
     - if: '$PIPELINE_TYPE == "LICENSE_PAGE_UPDATE_PIPELINE"'
 .build-package-on-all-os-vars:
-  SKIP_JOB_REGEX: '/SLES|Ubuntu-20.04|Docker|QA/'
+  SKIP_JOB_REGEX: '/Ubuntu-20.04|Docker|QA/'
   PIPELINE_TYPE: "${EDITION}_BRANCH_BUILD_PIPELINE"
   ALTERNATIVE_SOURCES: 'true'
   GITLAB_VERSION: ${GITLAB_VERSION}