ci: Add ci stage that checks wasm compilation.

Author: scottmarchant

.github/workflows/test.yaml

@@ -15,3 +15,12 @@ jobs:
     uses: graphqlswift/ci/.github/workflows/test.yaml@main
     with:
       include_android: false
+
+  wasm:
+    runs-on: ubuntu-latest
+    container: swift:6.1.0
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - run: swift build --swift-sdk wasm32-unknown-wasip1-threads
+        uses: swiftwasm/setup-swiftwasm@v2