refactor(pxe): switch Docker Compose module to v2

flake.nix

@@ -25,7 +25,7 @@
             bmake
             diffutils
             docker
-            docker-compose_1 # TODO upgrade to version 2
+            docker-compose
             dyff
             git
             go

metal/roles/pxe_server/tasks/main.yml

@@ -41,7 +41,7 @@
   loop: "{{ groups['metal'] }}"
 
 - name: Start the ephemeral PXE server
-  community.docker.docker_compose:
+  community.docker.docker_compose_v2:
     project_src: "{{ role_path }}/files"
     state: present
-    build: true
+    build: always