Investigate (and probably remove) use of threading in xblock/api.py

[ormsbee]

It doesn't look like this should be there at all, unless it's being used in some weird way as a re-export by things importing this module.

openedx-platform/openedx/core/djangoapps/xblock/api.py

Line 11 in 628c980

import threading # pylint: disable=unused-import # noqa: F401