base: Fix setting hostname on OpenBSD hosts

ansible.builtin.hostname seems to be broken on OpenBSD so set hostname
directly using /etc/myname

roles/base/tasks/OpenBSD.yml

@@ -1,4 +1,12 @@
 ---
+- name: set correct hostname
+  ansible.builtin.copy:
+    dest: /etc/myname
+    content: "{{ inventory_hostname }}\n"
+    mode: 0644
+    owner: root
+    group: "{{ ansible_wheel }}"
+
 - name: configure mirror for packages and updates
   ansible.builtin.copy:
     dest: /etc/installurl