Use Xcode 14 on CI

Author: crazytonyli

.buildkite/pipeline.yml

@@ -8,7 +8,7 @@ common_params:
         repo: "woocommerce/woocommerce-ios/"
   # Common environment values to use with the `env` key.
   - &common_env
-    IMAGE_ID: xcode-13.4.1
+    IMAGE_ID: xcode-14
 
 # This is the default pipeline – it will build and test the app
 steps: