github: add a multiplatform hello world workflow

Add a new workflow to build the hello world sample application on all
three supported platforms using the reusable setup action.

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>

.github/workflows/hello_world_multiplatform.yaml

@@ -0,0 +1,56 @@
+name: Hello World (Multiplatform)
+
+on:
+  push:
+    branches:
+      - main
+      - v*-branch
+      - collab-*
+  pull_request:
+    branches:
+      - main
+      - v*-branch
+      - collab-*
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          path: zephyr
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.11
+
+      - name: Setup Zephyr project
+        uses: fabiobaltieri/zephyr-setup@main
+        with:
+          app-path: zephyr
+          toolchains: all
+
+      - name: Build firmware
+        working-directory: zephyr
+        shell: bash
+        run: |
+          if [ "${{ runner.os }}" = "macOS" ]; then
+            EXTRA_TWISTER_FLAGS="-P native_posix --build-only"
+          elif [ "${{ runner.os }}" = "Windows" ]; then
+            EXTRA_TWISTER_FLAGS="-P native_posix --short-build-path -O/tmp/twister-out"
+          fi
+          west twister -T samples/hello_world -v $EXTRA_TWISTER_FLAGS
+
+      - name: Upload artifacts
+        if: failure()
+        uses: actions/upload-artifact@v3
+        with:
+          if-no-files-found: ignore
+          path:
+            zephyr/twister-out/*/samples/hello_world/sample.basic.helloworld/build.log