chore: update podspec version to 1.2.5

Author: hyochan

openiap.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'openiap'
-  s.version          = '1.2.6'
+  s.version          = '1.2.5'
   s.summary          = 'OpenIAP - Modern Swift library for in-app purchases'
   s.description      = <<-DESC
     OpenIAP is a modern Swift library for handling in-app purchases using StoreKit 2.