Update pyproject.toml

[amrothemich]

Switched pyproject license to dictionary type to address:

Getting requirements to build wheel: finished with status 'error'
error: subprocess-exited-with-error
× Getting requirements to build wheel did not run successfully.
│ exit code: 1
╰─> [95 lines of output]
configuration error: `project.license` must be valid exactly by one definition (2 matches found):
    - keys:
        'file': {type: string}
        required: ['file']
    - keys:
        'text': {type: string}
        required: ['text']

DESCRIPTION:
`Project license <https://peps.python.org/pep-0621/#license>`_.

GIVEN VALUE:
"Apache-2.0"

OFFENDING RULE: 'oneOf'

which was preventing installation via pip install git+https://github.com/unslothai/unsloth.git

[amrothemich]

@danielhanchen This part is ready now, thanks!

[danielhanchen]

Thanks!