add missing new line in multi line env variable

.github/workflows/build.yml

@@ -24,6 +24,7 @@ jobs:
           {
             echo 'CHANGELOG<<EOF'
             git log ${{ github.event.before }}...${{ github.event.after }} --pretty=format:"\[[%h](https://github.com/$GITHUB_REPOSITORY/commit/%H)\] %s (%cn)  "
+            echo ""
             echo EOF
           } >> "$GITHUB_ENV"
       - name: Set up JDK 17