fix macos ci setup for apple silicon runners

Author: IanButterworth

.github/workflows/ci.yml

@@ -26,14 +26,14 @@ jobs:
           - 'nightly'
         os:
           - ubuntu-latest
-          - macOS-latest
           - windows-latest
         arch:
           - x64
           - x86
-        exclude:
+        include:
           - os: macOS-latest
-            arch: x86
+            arch: aarch64
+            version: 'nightly'
     steps:
       - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v2