drop renovate

we now use gitea actions for it.

renovate.json

@@ -1,15 +0,0 @@
-{
-  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-  "extends": ["config:recommended"],
-  "lockFileMaintenance": { "enabled": true },
-  "nix": {
-    "enabled": true
-  },
-  "packageRules": [
-    {
-      "matchManagers": ["npm"],
-      "matchPaths": ["pkgs/clan-app/ui/**"],
-      "enabled": false
-    }
-  ]
-}