(CAT-2100) Add Debian 12 support

Author: shubhamshinde360

.fixtures.yml

@@ -9,7 +9,7 @@ fixtures:
     facts: 'https://github.com/puppetlabs/puppetlabs-facts.git'
     puppet_agent:
       repo: 'https://github.com/puppetlabs/puppetlabs-puppet_agent.git'
-      ref: v4.13.0
+      ref: v4.21.0
     provision: 'https://github.com/puppetlabs/provision.git'
   symlinks:
     accounts: "#{source_dir}"

metadata.json

@@ -45,7 +45,8 @@
       "operatingsystem": "Debian",
       "operatingsystemrelease": [
         "10",
-        "11"
+        "11",
+        "12"
       ]
     },
     {