Add Swift Macro Compatibility Check to CI (#3406)

* Add Swift Macro Compatibility Check GitHub Action

This PR adds a **Swift Macro Compatibility Check** GitHub Action to ensure that macro changes remain compatible across different versions of `swift-syntax`. The action automatically verifies compatibility with major `swift-syntax` versions (`509.0.0`, `510.0.0`, `600.0.0`), running builds and tests. It's also posible to turn on checking agains all versions of `swift-syntax`.

#### Key Benefits:
- **Automated Compatibility Checks**: No need to manually test changes across different `swift-syntax` versions—this is handled automatically in CI.
- **Prevents Breakages**: Helps avoid accidentally committing changes that break older versions.

* Use major versions only

* Use `v1` version

---------

Co-authored-by: Stephen Celis <stephen@stephencelis.com>

.github/workflows/ci.yml

@@ -113,3 +113,15 @@ jobs:
         run: make DERIVED_DATA_PATH=~/.derivedData SCHEME="Todos" xcodebuild
       - name: VoiceMemos
         run: make DERIVED_DATA_PATH=~/.derivedData SCHEME="VoiceMemos" xcodebuild
+
+  check-macro-compatibility:
+    name: Check Macro Compatibility
+    runs-on: macos-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Run Swift Macro Compatibility Check
+        uses: Matejkob/swift-macro-compatibility-check@v1
+        with:
+          run-tests: false
+          major-versions-only: true