add framework._non_static_mode temporarily for hackson; test=document_fix (#41220)

python/paddle/framework/__init__.py

@@ -47,6 +47,7 @@ from ..fluid.framework import set_flags  # noqa: F401
 from ..fluid.dygraph.base import enable_dygraph as disable_static  # noqa: F401
 from ..fluid.dygraph.base import disable_dygraph as enable_static  # noqa: F401
 from ..fluid.framework import _non_static_mode as in_dynamic_mode  # noqa: F401
+from ..fluid.framework import _non_static_mode  #  noqa: F401; temporary used for hackson
 from ..fluid.framework import _current_expected_place, _get_paddle_place  # noqa: F401
 from ..fluid.framework import dygraph_only  # noqa: F401
 from ..fluid.framework import convert_np_dtype_to_dtype_, _varbase_creator, OpProtoHolder  # noqa: F401