Merge pull request #2603 from ruby/workflow-2

Bundle update by github action

Author: soutaro

.github/workflows/bundle-update.yml

@@ -35,7 +35,7 @@ jobs:
           bundle lock --update
           git add Gemfile.lock
 
-          if git diff --cached --quiet; then
+          if git diff --cached --exit-code; then
             echo "No changes to commit, exiting."
             exit 0
           fi
@@ -56,4 +56,4 @@ jobs:
             --title "bundle update `/Gemfile`" \
             --body "Automated bundle update" \
             --head "$(git rev-parse --abbrev-ref HEAD)" \
-            --base "main"
+            --base "${{ github.event.repository.default_branch }}"