fix(ci): check dependabot PR user instead of actor

Author: caugner

.github/workflows/auto-merge.yml

@@ -8,7 +8,7 @@ on:
 jobs:
   auto-merge:
     runs-on: ubuntu-latest
-    if: github.actor == 'dependabot[bot]'
+    if: github.event.pull_request.user.login == 'dependabot[bot]'
 
     steps:
       - name: Dependabot metadata