apply PEP621

[zacharyburnett]

PEP621 (https://peps.python.org/pep-0621/) defines using the pyproject.toml file to store project metadata in the [project] table. This has several advantages over using setup.cfg or setup.py to store the project metadata, namely:

• consolidates metadata and configuration into one file; pyproject.toml is required by PEP517 (https://peps.python.org/pep-0517/) and many third party tools use it to store their configuration
• allows alternate build tools other than setuptools (such as hatch or meson) to read the same project metadata

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[jmr]

Could you give a bit more info than just "apply PEP 621"? I don't know anything about Python packaging, so a few sentences of explanation would be helpful.

https://google.github.io/eng-practices/review/developer/cl-descriptions.html#informative

[jmr]

@selimnairb This is moving the setup.cfg you added in #313 to pyproject.toml. Do you want to take a look?

[selimnairb]

@selimnairb This is moving the setup.cfg you added in #313 to pyproject.toml. Do you want to take a look?

@jmr Yes, I'll pull it down today and have a look.

[jmr]

Thanks!