CI: run Node tests on all supported versions

Switching back to ts-mocha/ts-node for the test-node script is required for it
to work with the different versions of Node (passing --import in NODE_OPTIONS
is not supported in older versions).

.github/workflows/tests.yml

@@ -8,12 +8,20 @@ on:
 
 jobs:
   test-node:
-    name: Node integration tests
+    strategy:
+      fail-fast: false # if tests for one version fail, continue with the rest
+      matrix:
+        node-version: [16.x, 18.x, '20.x', 'lts']
+        # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
+
+    name: Node integration tests (${{ matrix.node-version }})
     runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v3
     - uses: actions/setup-node@v3
+      with:
+        node-version: ${{ matrix.node-version }}
     - run: npm ci
     - run: npm run test-node