Update pyproject toml

[kwabenantim]

Description

Supports #303

Motivation and Context

Modernise setup.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Documentation checklist

• I have updated all documentation in the code where necessary.
• I have checked spelling in all (new) comments and documentation.
• I have added a note to RELEASE.md if relevant (new feature, breaking change, or notable bug fix).
• I have updated version & citation.txt & citation.cff version.

Testing

• Testing is done automatically and codecov shows test coverage
• This cannot be tested automatically