Attempt to fix automerging

See eksctl-io/eksctl#2485 (comment)

.github/workflows/automerge.yml

@@ -1,6 +1,6 @@
 name: Automerge
 on:
-  pull_request:
+  pull_request_target:
     types:
       - labeled
       - unlabeled
@@ -10,9 +10,6 @@ on:
       - ready_for_review
       - reopened
       - unlocked
-  pull_request_review:
-    types:
-      - submitted
   check_suite:
     types:
       - completed