CI: Up to node 18.x

.github/workflows/main.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Use Node.js
         uses: actions/setup-node@v1
         with:
-          node-version: '12.x'
+          node-version: '18.x'
 
       - name: Install all required dependencies
         run: yarn install