[pyproject.toml] Comment out 'platforms'
[pyproject.toml] Comment out 'platforms'

Poetry hasn't support platforms yet.
But, it appears in the code here:
<https://github.com/python-poetry/poetry/blob/845ae55c3c85714e4234c9ad46d3c8665f2592db/poetry/masonry/metadata.py#L12>

M157q/gettitle