Squash auto-merge Dependabot PRs (#783)

Author: wata727

.github/workflows/dependabot.yml

@@ -11,7 +11,7 @@ jobs:
     if: github.event.pull_request.user.login == 'dependabot[bot]'
     steps:
       - name: Enable auto-merge for Dependabot PRs
-        run: gh pr merge --auto --merge "$PR_URL"
+        run: gh pr merge --auto --squash "$PR_URL"
         env:
           PR_URL: ${{github.event.pull_request.html_url}}
           GH_TOKEN: ${{secrets.GITHUB_TOKEN}}