chore: run tests against node 18 (#381)

Author: SimenB

.github/workflows/nodejs.yml

@@ -9,14 +9,15 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [12.x, 14.x, 16.x]
+        node-version: [12.x, 14.x, 16.x, 18.x]
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v2
+      uses: actions/setup-node@v3
       with:
         node-version: ${{ matrix.node-version }}
+        cache: yarn
     - name: install, test, lint and typecheck
       run: |
         yarn