Use squash-merge for Dependabot PRs

Author: steveteuber

.github/workflows/dependabot.yml

@@ -20,7 +20,7 @@ jobs:
 
     - name: Enable auto-merge for Dependabot PRs
       if: ${{ steps.metadata.outputs.update-type != 'version-update:semver-major' }}
-      run: gh pr merge --auto --merge "$PR_URL"
+      run: gh pr merge --auto --squash "$PR_URL"
       env:
         PR_URL: ${{ github.event.pull_request.html_url }}
         GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}