fix a bug for wenet streaming model. (#1054)

* fix a bug for wenet streaming model.

The chunk shift was wrong.
See
https://github.com/wenet-e2e/wenet/blob/main/runtime/core/decoder/asr_model.cc#L15
and
https://github.com/wenet-e2e/wenet/blob/main/runtime/core/decoder/asr_model.cc#L28

@@ -132,7 +132,7 @@ jobs:
           export PATH=/c/hostedtoolcache/windows/Python/3.9.13/x64/bin:$PATH
           export PATH=/c/hostedtoolcache/windows/Python/3.10.11/x64/bin:$PATH
           export PATH=/c/hostedtoolcache/windows/Python/3.11.9/x64/bin:$PATH
-          export PATH=/c/hostedtoolcache/windows/Python/3.12.3/x64/bin:$PATH
+          export PATH=/c/hostedtoolcache/windows/Python/3.12.4/x64/bin:$PATH
 
           which sherpa-onnx
           sherpa-onnx --help

@@ -107,7 +107,7 @@ jobs:
           export PATH=/c/hostedtoolcache/windows/Python/3.9.13/x64/bin:$PATH
           export PATH=/c/hostedtoolcache/windows/Python/3.10.11/x64/bin:$PATH
           export PATH=/c/hostedtoolcache/windows/Python/3.11.9/x64/bin:$PATH
-          export PATH=/c/hostedtoolcache/windows/Python/3.12.3/x64/bin:$PATH
+          export PATH=/c/hostedtoolcache/windows/Python/3.12.4/x64/bin:$PATH
 
           sherpa-onnx --help
           sherpa-onnx-keyword-spotter --help

@@ -143,7 +143,7 @@ def main():
         (model.chunk_size - 1) * model.subsampling_factor + model.right_context + 1
     )
     chunk_length = int(chunk_length)
-    chunk_shift = int(model.required_cache_size)
+    chunk_shift = int(model.chunk_size * model.subsampling_factor)
     print(chunk_length, chunk_shift)
 
     num_frames = x.shape[0]

@@ -97,7 +97,9 @@ class OnlineWenetCtcModel::Impl {
            right_context_ + 1;
   }
 
-  int32_t ChunkShift() const { return required_cache_size_; }
+  int32_t ChunkShift() const {
+    return config_.wenet_ctc.chunk_size * subsampling_factor_;
+  }
 
   OrtAllocator *Allocator() const { return allocator_; }