chore: bump node version in tests

Newest hardhat doesnt support Node 16: https://hardhat.org/hardhat-runner/docs/reference/stability-guarantees#node.js-versions-support

.github/workflows/test.yml

@@ -30,7 +30,7 @@ jobs:
       - name: Setup Node Environment ⬢
         uses: actions/setup-node@v1
         with:
-          node-version: 16
+          node-version: 18
 
       - name: Install 🔧
         run: npm install