Specify runner tag for CI jobs

.gitlab/ci/build.gitlab-ci.yml

@@ -35,6 +35,8 @@
         - "merge_requests"
     - if: $CI_PIPELINE_SOURCE == "web" && ($BUILD_IMAGE_NAME == "" || $BUILD_IMAGE_NAME == null)
     - if: $CI_JOB_NAME == $BUILD_IMAGE_NAME
+  tags:
+    - docker-builder
 
 ansible:
   extends: .build