Change Dependabot PR merge action to peter-evans

Author: dermatz

.github/workflows/dependabot.yml

@@ -26,7 +26,7 @@ jobs:
 
     steps:
       - name: Auto-merge Dependabot PRs
-        uses: actions-ecosystem/action-merge@v2
+        uses: peter-evans/merge-pull-request@v4
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           merge_method: squash