update github ci to node 18

.github/workflows/tests.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Install Node.js
         uses: actions/setup-node@v3
         with:
-          node-version: 16.x
+          node-version: 18.x
       - name: Install root project dependencies
         run: npm install
       - name: Build and run tests