Mark de.systopia.recentitems obsolete

extension-compatibility.json

@@ -5,6 +5,9 @@
   "com.aghstrategies.slicknav": {
     "obsolete": "5.12"
   },
+  "de.systopia.recentitems": {
+    "obsolete": "5.12"
+  },
   "com.ixiam.modules.quicksearch": {
     "obsolete": "5.8"
   }