New features:
* added new 4-bit integer types: `ml_dtypes.int4` and `ml_dtypes.uint4`
Deprecations:
* `ml_dtypes.float8_e4m3b11` has been renamed to `ml_dtypes.float8_e4m3b11fnuz` for more
consistency with other dtype names. The former name will still be available until
version 0.3.0, but will raise a deprecation warning.