Update python-mypy to 0.782

Summary:
Full changelog here

Depends on D9515

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

Test Plan: Check for errors in pythons scripts located in mypy/test-data/samples/ and then run thonny.

Reviewers: Triage Team, JoshStrobl

Reviewed By: Triage Team, JoshStrobl

Subscribers: JoshStrobl

Differential Revision: https://dev.getsol.us/D9516