chore(renovate): use automerge preset and config simplification (#268)

* chore(renovate): use automerge preset and config simplification

https://coveord.atlassian.net/browse/cia-612

* fix preset extension

renovate.json

@@ -1,10 +1,10 @@
 {
-  "enabled": true,
   "extends": [
     "github>coveo/renovate-presets",
     ":semanticPrefixFixDepsChoreOthers",
     "helpers:pinGitHubActionDigests",
-    "schedule:earlyMondays"
+    "schedule:earlyMondays",
+    "github>coveo/renovate-presets//auto-merge.json"
   ],
   "packageRules": [
     {
@@ -13,9 +13,7 @@
       "groupSlug": "all"
     }
   ],
-  "rangeStrategy": "auto",
   "lockFileMaintenance": {
     "enabled": true
-  },
-  "automerge": true
+  }
 }