fix(run/django): use k8s-skaffold pack for image building

Author: glasnt

run/django/cloudmigrate.yaml

@@ -15,7 +15,7 @@
 # [START cloudrun_django_cloudmigrate_yaml_python]
 steps:
   - id: "Build Container Image"
-    name: buildpacksio/pack
+    name: gcr.io/k8s-skaffold/pack
     args: ["build", "${_IMAGE_NAME}", "--builder=gcr.io/buildpacks/builder"]
 
   - id: "Push Container Image"

run/django/e2e_test_setup.yaml

@@ -69,7 +69,7 @@ steps:
         --project ${PROJECT_ID}"
 
   - id: "Build Container Image"
-    name: buildpacksio/pack
+    name: gcr.io/k8s-skaffold/pack
     args: ["build", "${_IMAGE_NAME}", "--builder=gcr.io/buildpacks/builder",
       "--env", "GOOGLE_PYTHON_VERSION=${_PYTHON_VERSION}"]