Publish nightly manifests to new staging bucket

This PR starts publishing the nightly artifacts to the k8s-staging-cluster-api-aws bucket, instead of to the artifacts.k8s-staging-cluster-api-aws.appspot.com.

The latter is the backing bucket of the google container registry and will go away eventually when we migrate from the container registry to the artifact registry. It was never meant to be used to store files that are not part of container images.

Please note that the new location has a retention of 60 days (as of now). But that should be okay for nightly manifests.

Author: damdo

Makefile

@@ -91,7 +91,7 @@ endif
 # Release variables
 
 STAGING_REGISTRY ?= gcr.io/k8s-staging-cluster-api-aws
-STAGING_BUCKET ?= artifacts.k8s-staging-cluster-api-aws.appspot.com
+STAGING_BUCKET ?= k8s-staging-cluster-api-aws
 BUCKET ?= $(STAGING_BUCKET)
 PROD_REGISTRY := registry.k8s.io/cluster-api-aws
 REGISTRY ?= $(STAGING_REGISTRY)
@@ -631,6 +631,8 @@ release-alias-tag: # Adds the tag to the last build tag.
 
 .PHONY: upload-staging-artifacts
 upload-staging-artifacts: ## Upload release artifacts to the staging bucket
+	# Example manifest location: https://storage.googleapis.com/k8s-staging-cluster-api-aws/components/nightly_main_20240425/infrastructure-components.yaml
+	# Please note that these files are deleted after a certain period, at the time of this writing 60 days after file creation.
 	gsutil cp $(RELEASE_DIR)/* gs://$(BUCKET)/components/$(RELEASE_ALIAS_TAG)
 
 IMAGE_PATCH_DIR := $(ARTIFACTS)/image-patch