Use macos-15-intel for macos x64 tests

Author: christiangnrd

.github/workflows/CI.yml

@@ -27,7 +27,7 @@ jobs:
           - os: macos-latest
             arch: aarch64
             version: '1'
-          - os: macos-13
+          - os: macos-15-intel
             arch: x64
             version: '1'