chore: Fix the test.yml workflow to simply pick the latest stable Xcode

Author: kevinrenskers

.github/workflows/test.yml

@@ -11,16 +11,12 @@ on:
 jobs:
   test-xcode:
     runs-on: macos-latest
-    strategy:
-      matrix:
-        # see https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners#supported-software for versions
-        xcode:
-          - 15.2
 
     steps:
       - uses: actions/checkout@v2
-      - name: Select Xcode ${{ matrix.xcode }}
-        run: sudo xcode-select -s /Applications/Xcode_${{ matrix.xcode }}.app
+      - uses: maxim-lobanov/setup-xcode@v1
+        with:
+          xcode-version: latest-stable
       - name: Build
         run: swift build -v
       - name: Run tests