fix(ios): revert TensorFlow Lite Swift to 2.12.0

- Reverts iOS TensorFlow Lite Swift version from 2.16.1 to 2.12.0
 - Fixes CocoaPods compatibility issue where 2.16.1 was not available
 - Maintains iOS functionality while keeping Android 16KB page size support

Author: bhanuka96

ios/tflite_flutter.podspec

@@ -22,7 +22,7 @@ TensorFlow Lite plugin for Flutter apps.
 
   s.dependency 'Flutter'
 
-  tflite_version = '2.16.1'
+  tflite_version = '2.12.0'
   s.dependency 'TensorFlowLiteSwift', tflite_version
   s.dependency 'TensorFlowLiteSwift/Metal', tflite_version
   s.dependency 'TensorFlowLiteSwift/CoreML', tflite_version