mypy

55a88406 - Add a function to search for pyproject.toml in a project root (#16965)

Add a function to search for pyproject.toml in a project root (#16965) Here's a solution to fix https://github.com/python/mypy/issues/10613. The tests are covered. It adds the functionality of searching `pyproject.toml` recursively from the current directory up to a project root (directory with either `.git` or `.hg`) to `mypy`