Fix CI: upgrade to Node 18, pin eslint-plugin-github to 4.3.2, add eslint-plugin-import as direct dep

Author: Copilot

.github/workflows/nodejs.yml

@@ -8,10 +8,10 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
     - uses: actions/checkout@v2
-    - name: Use Node.js 14.x
+    - name: Use Node.js 18.x
       uses: actions/setup-node@v1
       with:
-        node-version: 14.x
+        node-version: 18.x
     - name: npm install, build, and test
       run: |
         npm install