Update the CircleCI macos runner.

Author: iddm

.circleci/config.yml

@@ -208,7 +208,7 @@ jobs:
 
   build-macos-x64:
     macos:
-      xcode: 14.2.0
+      xcode: 15.4.0
     resource_class: macos.x86.medium.gen2
     steps:
       - run: brew install openssl