mkcert certs: flat fetch destination.

tasks/certificate_from_private_ca.yml

@@ -22,7 +22,8 @@
     - name: Get the certificate and its key from the CA server
       ansible.builtin.fetch:
         src: "/srv/mkcert-ca/{{ item }}"
-        dest: "files/{{ item }}"
+        dest: "files/"
+        flat: true
       loop:
         - "{{ mkcert_cert_name }}"
         - "{{ mkcert_key_name }}"