chore: Try updating to macos-15 since macos-14 is not getting provisioned

Author: Marwes

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
     strategy:
       matrix:
         include:
-          - os: macos-14.0
+          - os: macos-15.0
           - os: windows-2025
             features: cmake-build,libz-static,curl-static
             rdkafka-sys-features: cmake-build,libz-static,curl-static