[Model] Add native full-duplex Nemotron VoiceChat serving (#6089)

Signed-off-by: Sysy <1370724210@qq.com>
Signed-off-by: sy03 <137072421@qq.com>
Co-authored-by: sy03 <137072421@qq.com>

tests/worker/test_gpu_ar_model_runner.py

@@ -1832,6 +1832,7 @@ class TestPreferModelSamplerNoneFallback:
             "hunyuan_image3",
             "minicpmo_4_5",
             "minimax_music3",
+            "nemotron_voicechat",
         }
         assert declarers == expected, (
             "The set of models declaring `prefer_model_sampler` changed:\n"