ci: update node version

Author: samuelmaddock

.github/workflows/test.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Setup Node
       uses: actions/setup-node@v1
       with:
-        node-version: '18.x'
+        node-version: '20.x'
 
     - name: Install dependencies
       run: |