fix the keras.io test

Author: haifeng-jin

.github/workflows/integration_tests.yml

@@ -32,5 +32,6 @@ jobs:
         run: |
           pip install -e ".[tensorflow-cpu,tests]" --progress-bar off --upgrade
           pip install jax[cpu] --progress-bar off --upgrade
+          pip install tensorflow==2.16.0rc0
       - name: Run the guides
         run: bash shell/run_guides.sh