[train] KTransformers SFT as backend engine for LLaMA-Factory (#9400)

Co-authored-by: jimmy128 <jimmy128@noreply.gitcode.com>
Co-authored-by: Yaowei Zheng <hiyouga@buaa.edu.cn>

src/llamafactory/extras/packages.py

@@ -82,6 +82,10 @@ def is_ray_available():
     return _is_package_available("ray")
 
 
+def is_kt_available():
+    return _is_package_available("ktransformers")
+
+
 def is_requests_available():
     return _is_package_available("requests")