Combine basic jobs to reduce Actions usage

.github/workflows/pr-checks.yml

@@ -9,20 +9,41 @@ on:
   workflow_dispatch:
 
 jobs:
-  check-js:
-    name: Check JS
-    runs-on: ubuntu-latest
-    timeout-minutes: 45
+  unit-tests:
+    name: Unit Tests
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
     permissions:
       contents: read
       security-events: write # needed to upload ESLint results
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 45
 
     steps:
-      - name: Checkout
-        uses: actions/checkout@v5
-
+      - uses: actions/checkout@v5
+      
       - name: Install dependencies
-        run: npm install
+        run: |
+          # Use the system Bash shell to ensure we can run commands like `npm install`
+          # that are not available in the default shell on Windows.
+          npm config set script-shell bash
+          npm install
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.11
+
+      - name: Verify compiled JS up to date
+        run: .github/workflows/script/check-js.sh
+
+      - name: Verify PR checks up to date
+        run: .github/workflows/script/verify-pr-checks.sh
+
+      - name: Run unit tests
+        run: npm test
 
       - name: Lint
         id: lint
@@ -30,54 +51,11 @@ jobs:
 
       - name: Upload sarif
         uses: github/codeql-action/upload-sarif@v3
+        if: matrix.os == 'ubuntu-latest'
         with:
           sarif_file: eslint.sarif
           category: eslint
 
-      - name: Check generated JS
-        run: .github/workflows/script/check-js.sh
-
-  check-file-contents:
-    name: Check file contents
-    permissions:
-      contents: read
-    runs-on: ubuntu-latest
-    timeout-minutes: 45
-
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v5
-
-      - name: Set up Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: 3.11
-
-      # Ensure the generated PR check workflows are up to date.
-      - name: Verify PR checks up to date
-        run: .github/workflows/script/verify-pr-checks.sh
-
-  npm-test:
-    name: Unit Test
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
-    permissions:
-      contents: read
-    runs-on: ${{ matrix.os }}
-    timeout-minutes: 45
-
-    steps:
-      - uses: actions/checkout@v5
-      - name: npm test
-        run: |
-          # Run any commands referenced in package.json using Bash, otherwise
-          # we won't be able to find them on Windows.
-          npm config set script-shell bash
-          npm install
-          npm test
-
   check-node-version:
     if: github.event.pull_request
     name: Check Action Node versions