[FEA] pylance/pyright

[lmeyerov]

Is your feature request related to a problem? Please describe. MyPy is frustratingly slow, it'd be great to try something supposedly faster like pylance/pyright

Depending on success, we may want to move to that for dev and only run mypy for ci

To get started, just some sort of bin script, and a round of basic fix attempts, would go far!