Specify architecture for emulator in CI

Author: marcprux

.github/workflows/ci.yml

@@ -30,9 +30,16 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        - os: 'macos-26'
-          swift: '6.2'
-          arch: 'arm64-v8a'
+        include:
+          - os: 'macos-26'
+            swift: '6.2'
+            arch: 'arm64-v8a'
+          - os: 'macos-13'
+            swift: '6.1'
+            arch: 'x86_64'
+          - os: 'macos-13'
+            swift: '6.2'
+            arch: 'x86_64'
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4