Move setup to build multiarch containers into dedicated role

This change moves the QEMU configuration for multiarch builds into a
dedicated role. Furthermore the execution will always be treated as
unchanged, unless an error occured!

roles/multiarch-container-builds/tasks/main.yml

@@ -0,0 +1,5 @@
+- name: Ensure QEMU configuration for multiarch podman builds
+  become: yes
+  shell: podman run --rm --privileged docker.io/multiarch/qemu-user-static --reset -p yes
+  changed_when: False
+  when: ansible_os_family == 'Debian'