feat: added visionOS target and test target

Author: desusai7

SimpleKeychain.podspec

@@ -16,6 +16,7 @@ Pod::Spec.new do |s|
   s.osx.deployment_target = '11.0'
   s.tvos.deployment_target = '13.0'
   s.watchos.deployment_target = '7.0'
+  s.visionos.deployment_target = '1.0'
 
   s.source_files = 'SimpleKeychain/*.swift'
   s.swift_versions = ['5.7', '5.8']