Update nb_stl.h

Author: MaxwellGengYF

include/nanobind/nb_stl.h

@@ -15,7 +15,6 @@ using luisa::span;
 using luisa::unique_ptr;
 using luisa::shared_ptr;
 using luisa::vector;
-using eastl::vector;
 template <typename T, typename Alloc>
 using stl_vector = ::std::vector<T, Alloc>;
 using luisa::function;