Vulture

* Add basic `match` statement support (kreathon, 276, 291).

* Mark imports in `__all__` as used (kreathon, 172, 282).
* Add whitelist for `pint.UnitRegistry.default_formatter` (Ben Elliston, 258).

* Print absolute filepaths as relative again (as in version 2.1 and before)
if they are below the current directory (The-Compiler, 246).
* Run tests and add PyPI trove for Python 3.10 (chayim, 266).
* Allow using the `del` keyword to mark unused variables (sshishov, 279).

* Add [pre-commit](https://pre-commit.com) hook (Clément Robert, #244).

* Only parse format strings when being used with `locals()` (jingw, 225).
* Don't override paths in pyproject.toml with empty CLI paths (bcbnz, 228).
* Run continuous integration tests for Python 3.9 (ju-sh, 232).
* Use pathlib internally (ju-sh, 226).

* Treat `getattr/hasattr(obj, "constant_string", ...)` as a reference to
`obj.constant_string` (jingw, 219).
* Fix false positives when assigning to `x.some_name` but reading via
`some_name`, at the cost of potential false negatives (jingw, 221).
* Allow reading options from `pyproject.toml` (Michel Albert, 164, 215).