Support non-streaming zipformer CTC ASR models (#2340)

This PR adds support for non-streaming Zipformer CTC ASR models across 
multiple language bindings, WebAssembly, examples, and CI workflows.

- Introduces a new OfflineZipformerCtcModelConfig in C/C++, Python, Swift, Java, Kotlin, Go, Dart, Pascal, and C# APIs
- Updates initialization, freeing, and recognition logic to include Zipformer CTC in WASM and Node.js
- Adds example scripts and CI steps for downloading, building, and running Zipformer CTC models

Model doc is available at
https://k2-fsa.github.io/sherpa/onnx/pretrained_models/offline-ctc/icefall/zipformer.html

wasm/vad-asr/app-vad-asr.js

@@ -117,6 +117,10 @@ function initOfflineRecognizer() {
     };
   } else if (fileExists('dolphin.onnx')) {
     config.modelConfig.dolphin = {model: './dolphin.onnx'};
+  } else if (fileExists('zipformer-ctc.onnx')) {
+    // you need to rename model.int8.onnx from zipformer CTC to
+    // zipformer-ctc.onnx
+    config.modelConfig.zipformerCtc = {model: './zipformer-ctc.onnx'};
   } else {
     console.log('Please specify a model.');
     alert('Please specify a model.');