Make Wolfi a part of Docker packaging (#5062)

* New images with `-wolfi` suffix are created
* The `-cloud` image is now based on Wolfi
* Refactored the packaging spec for better readability
* Fixed ignored architecture flags when building Docker
images. Building ARM64 on AMD64 and AMD64 or ARM64 is now possible

Author: rdner

changelog/fragments/1720208209-add-docker-wolfi.yaml

@@ -0,0 +1,3 @@
+kind: security
+summary: Add Wolfi docker image to packaging, the cloud image is now based on Wolfi
+component: "elastic-agent"