Ensure build number is available as an output.

Author: freakboy3742

.github/workflows/update-binary.yml

@@ -34,6 +34,9 @@ jobs:
         echo "BUILD_NUMBER=${BUILD_NUMBER}" | tee -a $GITHUB_ENV
         echo "STUB_PREFIX=${STUB_PREFIX}" | tee -a $GITHUB_ENV
 
+        # Expose BUILD_NUMBER as a step output so it can be consumed as a job output
+        echo "BUILD_NUMBER=${BUILD_NUMBER}" | tee -a $GITHUB_OUTPUT
+
     - name: Checkout Template
       uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0  # v7.0.0
       with: