Update python-traitlets to 5.0.5

Summary:
Full changelog here

Depends on D9972

Signed-off-by: Algent Albrahimi <algent@protonmail.com>

Test Plan: Run a couple of scripts in spyder3.

Reviewers: Triage Team, JoshStrobl

Reviewed By: Triage Team, JoshStrobl

Subscribers: JoshStrobl

Differential Revision: https://dev.getsol.us/D9973