[infra] Update GitHub workflow

- Pick the same compiler version that internal CI runs with.
- Pick the nigthly node.js version, so all required features are
  available (--wasm-allow-mixed-eh-for-testing is not available in
  node.js v24).
- Merge the configuration for MacOS and Linux.

Change-Id: I9fe0dfde89380f85efca94f270189bc5c79bd75c
Reviewed-on: https://chrome-internal-review.googlesource.com/c/v8/fuzzilli/+/8469996
Commit-Queue: Matthias Liedtke <mliedtke@google.com>
Reviewed-by: Samuel Groß <saelo@google.com>

Author: Liedtke

.github/workflows/swift.yml

@@ -7,21 +7,20 @@ on:
     branches: [ main ]
 
 jobs:
-  macOS:
-    runs-on: macos-latest
+  build:
+    strategy:
+      matrix:
+        os: [macos-latest, ubuntu-latest]
 
-    steps:
-      - uses: actions/checkout@v2
-      - name: Build
-        run: swift build -v
-      - name: Run tests
-        run: swift test -v
-
-  linux:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
 
     steps:
-      - uses: swift-actions/setup-swift@v1
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 25-nightly
+      - uses: swift-actions/setup-swift@v2
+        with:
+          swift-version: "6.0.3"
       - name: Swift Version
         run: swift --version
       - uses: actions/checkout@v2