Remove windos-img-promoter-cert secret

The secret was manually added, and has been manually removed. This is
removing the supporting infra/gcp scripting.

infra/gcp/ensure-staging-storage.sh

@@ -115,10 +115,6 @@ RELEASE_STAGING_PROJECTS=(
     releng
 )
 
-WINDOWS_REMOTE_DOCKER_PROJECTS=(
-    e2e-test-images
-)
-
 if [ $# = 0 ]; then
     # default to all staging projects
     set -- "${STAGING_PROJECTS[@]}"
@@ -260,28 +256,6 @@ for repo in "${RELEASE_STAGING_PROJECTS[@]}"; do
     ) 2>&1 | indent
 done
 
-# Special case: Empower GCB in k8s-staging-e2e-test-images to access secrets
-#               that were manually added to k8s-infra-prow-trusted
-color 6 "Configuring special cases for GCB access to windows-img-promoter-cert secrets"
-for repo in "${WINDOWS_REMOTE_DOCKER_PROJECTS[@]}"; do
-    (
-        PROJECT="k8s-staging-${repo}"
-        SECRET_PROJECT="k8s-infra-prow-build-trusted"
-        SECRET_GROUP="windows-img-promoter-cert"
-        for secret in $(gcloud secrets list \
-                        --format="value(name)" \
-                        --project="${SECRET_PROJECT}" \
-                        --filter="labels.secret-group=${SECRET_GROUP}"); do
-          color 6 "Empowering ${PROJECT}'s GCB service account to access secret ${secret} in ${SECRET_PROJECT}"
-          gcloud secrets add-iam-policy-binding \
-            "${secret}" \
-            --project="${SECRET_PROJECT}" \
-            --member="serviceAccount:$(gcb_service_account_email "k8s-staging-e2e-test-images")" \
-            --role="roles/secretmanager.secretAccessor"
-        done
-    ) 2>&1 | indent
-done
-
 # Special case: In order for ci-kubernetes-build to run on k8s-infra-prow-build,
 #               it needs write access to gcr.io/k8s-staging-ci-images. For now,
 #               we will grant the prow-build service account write access. Longer