Attempt to fix oci-build-task config

See gh-24197

ci/parameters.yml

@@ -12,3 +12,4 @@ concourse-url: "https://ci.spring.io"
 bintray-subject: "spring"
 bintray-repo: "jars"
 task-timeout: 2h00m
+ 

ci/pipeline.yml

@@ -209,20 +209,21 @@ jobs:
   plan:
   - get: ci-images-git-repo
     trigger: true
+  - get: git-repo
   - in_parallel:
     - task: build-ci-image
       privileged: true
-      file: ci-images-git-repo/ci/tasks/build-ci-image.yml
+      file: git-repo/ci/tasks/build-ci-image.yml
       vars:
         ci-image-name: ci-image
     - task: build-ci-image-jdk11
       privileged: true
-      file: ci-images-git-repo/ci/tasks/build-ci-image.yml
+      file: git-repo/ci/tasks/build-ci-image.yml
       vars:
         ci-image-name: ci-image-jdk11
     - task: build-ci-image-jdk15
       privileged: true
-      file: ci-images-git-repo/ci/tasks/build-ci-image.yml
+      file: git-repo/ci/tasks/build-ci-image.yml
       vars:
         ci-image-name: ci-image-jdk15
   - in_parallel:

ci/tasks/build-ci-image.yml

@@ -13,5 +13,6 @@ caches:
 params:
   CONTEXT: ci-images-git-repo/ci/images
   DOCKERFILE: ci-images-git-repo/ci/images/((ci-image-name))/Dockerfile
+  REGISTRY_MIRRORS: ((dockerhub-registry-mirror))
 run:
   path: build