Delete open3d reference in __init__.py to fix open3d = in stubgen.

Author: timohl

python/open3d/__init__.py

@@ -212,4 +212,4 @@ def _jupyter_nbextension_paths():
 
 if sys.platform == "win32":
     _win32_dll_dir.close()
-del os, sys, CDLL, load_cdll, find_library, Path, warnings, _insert_pybind_names
+del os, sys, CDLL, load_cdll, find_library, Path, warnings, _insert_pybind_names, open3d