Switch iOS back to macos-15-intel

Author: radarhere

.github/workflows/wheels.yml

@@ -104,7 +104,7 @@ jobs:
             cibw_arch: arm64_iphonesimulator
           - name: "iOS x86_64 simulator"
             platform: ios
-            os: macos-26-intel
+            os: macos-15-intel
             cibw_arch: x86_64_iphonesimulator
     steps:
       - uses: actions/checkout@v6