Use dash instead of underscore for extras.
The new `METADATA` specification disallows use of underscore and automatically converts any usage of them to dash.
https://packaging.python.org/en/latest/specifications/core-metadata/#provides-extra-multiple-use
This should fix the following error: https://github.com/jax-ml/jax/issues/27874 from appearing in future JAX releases
PiperOrigin-RevId: 746546162
