Try compact.

Author: desrosj

.github/workflows/slack-notifications.yml

@@ -159,9 +159,9 @@ jobs:
             --arg ref_name "${CURRENT_BRANCH}" \
             --arg run_url "https://github.com/WordPress/wordpress-develop/actions/runs/${GITHUB_RUN_ID}/attempts/${GITHUB_RUN_ATTEMPT}" \
             --arg commit_message "${COMMIT_MSG}" \
-            '{workflow_name: $workflow_name, ref_name: $ref_name, run_url: $run_url, commit_message: $commit_message}'
+            '{workflow_name: $workflow_name, ref_name: $ref_name, run_url: $run_url, commit_message: $commit_message}' | jq -c .
           )"
-          echo "payload=${PAYLOAD}" >> "$GITHUB_OUTPUT"
+          echo "payload=$PAYLOAD" >> "$GITHUB_OUTPUT"
         env:
           COMMIT_MSG: ${{ steps.commit-message.outputs.commit_message_escaped }}