feat: update incus build process

- ensure unkin-ca-certificates are installed
- find the default incus remote and use that for images
- dont set publish_remote_name
- build incus images for the base image
- build puppet-base image for incus only
- ensure builds are made with the `build` profile

library/sources.pkr.hcl

@@ -7,5 +7,5 @@ source "docker" "os" {
 source "incus" "os" {
   image = var.incus_source
   output_image = local.incus_output_image
-  publish_remote_name = "incus-images"
+  profile = "build"
 }