dokuwiki: find installed PHP version without running commands

So that it works in check mode.

roles/dokuwiki/tasks/php.yml

@@ -2,14 +2,12 @@
   package:
     name: acl,php,php-fpm
 
-- name: Find PHP package
+- name: Get installed packages
-  command: apk info -e php
+  package_facts:
-  register: php_package
-  changed_when: false
 
 - name: Set PHP version
   set_fact:
-    php_version: "{{ php_package.stdout | regex_search('[0-9.]+') }}"
+    php_version: "{{ ansible_facts.packages | select('match', '^php[0-9]+$') | first | replace('php', '') }}"
 
 - name: Set PHP-FPM settings
   lineinfile: