[CI] Fix nightly demo app build

Author: testableapple

.github/workflows/cron-checks.yml

@@ -94,7 +94,7 @@ jobs:
           - xcode: 16.4
             os: macos-15
           - xcode: 16.0
-            os: macos-15
+            os: macos-14
       fail-fast: false
     runs-on: ${{ matrix.os }}
     steps: