ci: bump node version for playground (#716)

Author: hishamhm

.github/workflows/playground.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [16.x]
+        node-version: [18.x]
     steps:
     - uses: actions/checkout@v1
       with: