Auto-merge version bump PRs

.github/workflows/build.yaml

@@ -57,11 +57,12 @@ jobs:
           git add VERSION
           git commit -m "Bump version to ${{ steps.check.outputs.version }}"
           git push origin "$branch"
-          gh pr create \
+          pr_url=$(gh pr create \
             --title "Bump proton-bridge to ${{ steps.check.outputs.version }}" \
-            --body "Auto-detected new upstream release. Merging will trigger the build pipeline." \
+            --body "Auto-detected new upstream release." \
             --base master \
-            --head "$branch"
+            --head "$branch")
+          gh pr merge "$pr_url" --squash --auto
 
   test:
     runs-on: ubuntu-latest