Revert "[CI] Update xcode to 26.0.1 on circleci (#16201)" (#16236)

This reverts commit e3e1286.

Author: straight-shoota

.circleci/config.yml

@@ -81,7 +81,7 @@ jobs:
 
   test_darwin:
     macos:
-      xcode: 26.0.1
+      xcode: 15.4.0
     environment:
       <<: *env
       TRAVIS_OS_NAME: osx
@@ -285,7 +285,7 @@ jobs:
 
   dist_darwin:
     macos:
-      xcode: 26.0.1
+      xcode: 15.3.0
     shell: /bin/bash --login -eo pipefail
     steps:
       - restore_cache: