Packer bootstrap tweaks

Much speed by using our Geo mirror + maximum freshness by not hard coding the bootstrap version anymore + extreme future-proofness by creating the temporary server with Ubuntu 22.04. ️

playbooks/tasks/install_arch.yml

@@ -9,5 +9,5 @@
   roles:
     - install_arch
   vars:
-    - bootstrap_version: "2022.03.01"
+    - bootstrap_version: "latest"
     - sshd_enable_includes: false