Modernize setuptools usage in pyproject.toml...
Modernize setuptools usage in pyproject.toml
1. Remove the redundant `wheel` dependency. The setuptools build
backend has been adding it automatically since day one, and it was
explicitly specified in the docs as a mistake. See:
https://github.com/pypa/setuptools/commit/f7d30a9529378cf69054b5176249e5457aaf640a
2. Replace the legacy backend with the regular backend. The legacy
backend was only intended to be used implicitly when `pyproject.toml`
does not specify only, and was not supposed to be specified
explicitly there. See:
https://github.com/pypa/setuptools/issues/1689
3. Prepend the current directory to `sys.path` as required for
`setup.py` to reliably import `setupbase`. The non-legacy backend
no longer does this for us.
