Try to upgrade node version to 18

Author: Michael O'Cleirigh

.github/workflows/build_esp32.yml

@@ -21,7 +21,10 @@ jobs:
           apt update
           apt install git
           git config --global --add safe.directory /__w/tensorflow-micropython-examples/tensorflow-micropython-examples
-          
+      - name: install node
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 18  
       - name: Checkout repository
         uses: actions/checkout@v2
       - name: Prepare to Build Tensorflow Micropython Firmware for ESP32