Fork and patch php_fpm_pools plugin to work with proper python3 command

checkmk/checkmk-files/php_fpm_pools → checkmk/custom-files/php_fpm_pools

-#!/usr/bin/env python
+#!/usr/bin/env python3
 # -*- encoding: utf-8; py-indent-offset: 4 -*-
 # +------------------------------------------------------------------+
 # |             ____ _               _        __  __ _  __           |

checkmk/debian/php_fpm_pools/init.sls

 phpfpm_status_plugin:
   file.managed:
     - name: /usr/lib/check_mk_agent/plugins/php_fpm_pools
-    - source: salt://checkmk/checkmk-files/php_fpm_pools
+    - source: salt://checkmk/custom-files/php_fpm_pools
     - mode: 755
     - user: root
     - group: root