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

sherpa-onnx/c-api/c-api.cc

@@ -484,6 +484,9 @@ static sherpa_onnx::OfflineRecognizerConfig GetOfflineRecognizerConfig(
   recognizer_config.model_config.dolphin.model =
       SHERPA_ONNX_OR(config->model_config.dolphin.model, "");
 
+  recognizer_config.model_config.zipformer_ctc.model =
+      SHERPA_ONNX_OR(config->model_config.zipformer_ctc.model, "");
+
   recognizer_config.lm_config.model =
       SHERPA_ONNX_OR(config->lm_config.model, "");
   recognizer_config.lm_config.scale =

sherpa-onnx/c-api/c-api.h

@@ -451,6 +451,10 @@ SHERPA_ONNX_API typedef struct SherpaOnnxOfflineDolphinModelConfig {
   const char *model;
 } SherpaOnnxOfflineDolphinModelConfig;
 
+SHERPA_ONNX_API typedef struct SherpaOnnxOfflineZipformerCtcModelConfig {
+  const char *model;
+} SherpaOnnxOfflineZipformerCtcModelConfig;
+
 SHERPA_ONNX_API typedef struct SherpaOnnxOfflineModelConfig {
   SherpaOnnxOfflineTransducerModelConfig transducer;
   SherpaOnnxOfflineParaformerModelConfig paraformer;
@@ -474,6 +478,7 @@ SHERPA_ONNX_API typedef struct SherpaOnnxOfflineModelConfig {
   SherpaOnnxOfflineMoonshineModelConfig moonshine;
   SherpaOnnxOfflineFireRedAsrModelConfig fire_red_asr;
   SherpaOnnxOfflineDolphinModelConfig dolphin;
+  SherpaOnnxOfflineZipformerCtcModelConfig zipformer_ctc;
 } SherpaOnnxOfflineModelConfig;
 
 SHERPA_ONNX_API typedef struct SherpaOnnxOfflineRecognizerConfig {

sherpa-onnx/c-api/cxx-api.cc

@@ -252,6 +252,9 @@ OfflineRecognizer OfflineRecognizer::Create(
 
   c.model_config.dolphin.model = config.model_config.dolphin.model.c_str();
 
+  c.model_config.zipformer_ctc.model =
+      config.model_config.zipformer_ctc.model.c_str();
+
   c.lm_config.model = config.lm_config.model.c_str();
   c.lm_config.scale = config.lm_config.scale;
 

sherpa-onnx/c-api/cxx-api.h

@@ -241,6 +241,10 @@ struct SHERPA_ONNX_API OfflineDolphinModelConfig {
   std::string model;
 };
 
+struct SHERPA_ONNX_API OfflineZipformerCtcModelConfig {
+  std::string model;
+};
+
 struct SHERPA_ONNX_API OfflineMoonshineModelConfig {
   std::string preprocessor;
   std::string encoder;
@@ -267,6 +271,7 @@ struct SHERPA_ONNX_API OfflineModelConfig {
   OfflineMoonshineModelConfig moonshine;
   OfflineFireRedAsrModelConfig fire_red_asr;
   OfflineDolphinModelConfig dolphin;
+  OfflineZipformerCtcModelConfig zipformer_ctc;
 };
 
 struct SHERPA_ONNX_API OfflineLMConfig {