BLD: update build system and use pyproject.toml

[coveralls]

Pull Request Test Coverage Report for Build 8043861284

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 97.464%

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Totals
Change from base Build 7986188385:	0.0%
Covered Lines:	6533
Relevant Lines:	6703

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💛 - Coveralls

[damonge]

@fangchenli let me know if you'd like me or someone else to review this.