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
- only build 9.5+ for incus
- prevent the build system from building images twice

ci/build.sh

@@ -12,7 +12,7 @@ fi
 # Run `make all` if there are changes in builds/
 if [ -n "$builds_changes" ]; then
   echo "Changes detected in builds/. Running 'make all'..."
-  make all
+  make all && exit 0 || exit 1
 fi
 
 # Run specific `make` commands for each changed file in images/