Improve CI config (#115)

- Use floating runtimes
- Break steps into individual runs
- Run on pull_request

.github/workflows/nodejs.yml

@@ -1,30 +1,26 @@
 name: Node CI
 
-on: [push]
+on: [push, pull_request]
 
 jobs:
   build:
 
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     timeout-minutes: 5
 
     strategy:
       matrix:
-        node-version: [18.x]
+        node-version: ['lts/*']
 
     steps:
     - uses: actions/checkout@v4
     - name: Use Node.js ${{ matrix.node-version }}
       uses: actions/setup-node@v3
       with:
         node-version: ${{ matrix.node-version }}
-    - name: npm install, build
-      run: |
-        npm install
-        npm run build --if-present
-        npm run lint
-      env:
-        CI: true
+    - run: npm install
+    - run: npm run build --if-present
+    - run: npm run lint
     - name: Run tape tests
       run: |
         xvfb-run --server-args="-screen 0 1920x1080x24" npm run ci:test:tape-run