install_arch: verify bootstrap image signature

Fixes #458 (closed).

roles/install_arch/tasks/main.yml

@@ -51,12 +51,10 @@
 
 - name: Get pierre's key
   ansible.builtin.command: gpg --locate-keys pierre@archlinux.de
-  register: valid_key
   changed_when: false
 
 - name: Get signature verification output
-  command: gpg --keyserver-options auto-key-retrieve --verify archlinux-bootstrap-x86_64.tar.gz.sig
-  register: gpg_info
+  command: gpg --verify archlinux-bootstrap-x86_64.tar.gz.sig
   changed_when: false
 
 - name: Extract boostrap image  # noqa risky-file-permissions
@@ -65,7 +63,6 @@
     dest: /tmp
     remote_src: true
     creates: /tmp/root.x86_64
-  when: valid_key.stdout_lines[1] | trim == gpg_info.stderr_lines[2].split()[-1] | trim
 
 - name: Copy resolv.conf to bootstrap chroot
   copy: remote_src=true src=/etc/resolv.conf dest=/tmp/root.x86_64/etc/resolv.conf owner=root group=root mode=0644