upgrade CI to node 18 LTS

.github/workflows/nodejs.yml

@@ -6,10 +6,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-    - name: Use Node.js 12.x
+      - name: Use Node.js 18.x
         uses: actions/setup-node@v1
         with:
-        node-version: 12.x
+          node-version: 18.x
       - name: npm install, build, and test
         run: |
           npm install

.github/workflows/publish.yml

@@ -11,7 +11,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
         with:
-          node-version: 14
+          node-version: 18
           registry-url: https://registry.npmjs.org/
           cache: npm
       - run: npm ci