VPA: Fix the pipeline definition to use the upstream Dockerfiles

.ci/pipeline_definitions

@@ -103,38 +103,17 @@ vertical-pod-autoscaler:
         - linux/arm64
         dockerimages:
           vpa-recommender:
-            inputs:
-              repos:
-                source: ~ # default
-              steps:
-                build: ~
             image: europe-docker.pkg.dev/gardener-project/snapshots/gardener/autoscaler/vertical-pod-autoscaler/vpa-recommender
-            dockerfile: 'Dockerfile.recommender'
-            dir: 'vertical-pod-autoscaler'
+            dockerfile: 'Dockerfile'
+            dir: 'vertical-pod-autoscaler/pkg/recommender'
           vpa-updater:
-            inputs:
-              repos:
-                source: ~ # default
-              steps:
-                build: ~
             image: europe-docker.pkg.dev/gardener-project/snapshots/gardener/autoscaler/vertical-pod-autoscaler/vpa-updater
-            dockerfile: 'Dockerfile.updater'
-            dir: 'vertical-pod-autoscaler'
+            dockerfile: 'Dockerfile'
+            dir: 'vertical-pod-autoscaler/pkg/updater'
           vpa-admission-controller:
-            inputs:
-              repos:
-                source: ~ # default
-              steps:
-                build: ~
             image: europe-docker.pkg.dev/gardener-project/snapshots/gardener/autoscaler/vertical-pod-autoscaler/vpa-admission-controller
-            dockerfile: 'Dockerfile.admissioncontroller'
-            dir: 'vertical-pod-autoscaler'
-    steps:
-      test:
-        image: 'golang:1.20.5'
-      build:
-        image: 'golang:1.20.5'
-        output_dir: 'binary'
+            dockerfile: 'Dockerfile'
+            dir: 'vertical-pod-autoscaler/pkg/admission-controller'
   jobs:
     release:
       traits: