ci: use kaniko builder

ci/gcp.lib.yml

@@ -371,21 +371,26 @@ serial: true
 plan:
 - {get: gcp-pipeline-image-def, trigger: true}
 - task: build
-  privileged: true
   config:
     platform: linux
     image_resource:
       type: registry-image
       source:
-        repository: vito/oci-build-task
+        repository: gcr.io/kaniko-project/executor
+        tag: debug
     inputs:
     - name: gcp-pipeline-image-def
     outputs:
     - name: image
-    params:
-      CONTEXT: gcp-pipeline-image-def/ci/image/gcp
     run:
-      path: build
+      path: /kaniko/executor
+      args:
+      - --context=gcp-pipeline-image-def/ci/image/gcp
+      - --use-new-run
+      - --single-snapshot
+      - --cache=false
+      - --no-push
+      - --tar-path=image/image.tar
 - put: gcp-pipeline-image
   params:
     image: image/image.tar