Update Xcode CI image and Ruby Gems

Author: spencertransier

.buildkite/pipeline.yml

@@ -1,9 +1,9 @@
 # Nodes with values to reuse in the pipeline.
 common_params:
   plugins: &common_plugins
-    - automattic/a8c-ci-toolkit#3.3.0
+    - automattic/a8c-ci-toolkit#3.7.1
   env: &common_env
-    IMAGE_ID: xcode-15.0.1
+    IMAGE_ID: xcode-16.1
 
 # This is the default pipeline – it will build and test the pod
 steps:

Gemfile

@@ -6,4 +6,4 @@ gem 'cocoapods', '~> 1.11'
 gem 'cocoapods-check', '~> 1.1'
 gem 'danger-dangermattic', '~> 1.0'
 gem 'fastlane', '~> 2.189'
-gem 'fastlane-plugin-wpmreleasetoolkit', '~> 9.2'
+gem 'fastlane-plugin-wpmreleasetoolkit', '~> 12.3'