(maint) drop support for puppet < 7

Author: h0tw1r3

metadata.json

@@ -69,7 +69,7 @@
   "requirements": [
     {
       "name": "puppet",
-      "version_requirement": ">= 4.10.0 < 9.0.0"
+      "version_requirement": ">= 7.0.0 < 9.0.0"
     }
   ],
   "pdk-version": "3.0.1",