mypy: support 'no_implicit_optional', 'no_implicit_reexport'

[mishamsk]

Area with issue?

JSON Schema

✔️ Expected Behavior

Support both 'no_implicit_optional' and 'no_implicit_reexport', both of which are valid and documented (see doc)

❌ Actual Behavior

In vs code (via Even Better TOML extension):

Additional properties are not allowed ('no_implicit_optional', 'no_implicit_reexport' were unexpected)Even Better TOML
Additional properties are not allowed ('no_implicit_optional', 'no_implicit_reexport' were unexpected)Even Better TOML

YAML or JSON file that does not work.

[[tool.mypy.overrides]]
no_implicit_optional = true
no_implicit_reexport = true

IDE or code editor.

Visual Studio Code

Are you making a PR for this?

Yes, I will create a PR.

[hyperupcall]

Related to #3467