[JIT Kernel] Migrate dsv3_router_gemm from AOT sgl-kernel to JIT kernel (#21531)

Co-authored-by: Guohao Shao <shao.gh.98@gmail.com>
Co-authored-by: Brayden Zhong <brayden@radixark.ai>

sgl-kernel/include/sgl_kernel_ops.h

@@ -251,7 +251,6 @@ void bmm_fp8(
     at::Tensor B_scale,
     at::Tensor workspace_buffer,
     int64_t cublas_handle);
-void dsv3_router_gemm(torch::Tensor& output, const torch::Tensor& mat_a, const torch::Tensor& mat_b);
 void dsv3_fused_a_gemm(torch::Tensor& output, torch::Tensor const& mat_a, torch::Tensor const& mat_b);
 
 torch::Tensor gptq_gemm(