feat: port pyclient build config to pyproject.toml

[dshemetov]

Summary:

I hoped the more modern config's dynamic metadata would work, but it only works if __version__ is defined explicitly in __init__.py, not imported from delphi_epidata.py (importing delphi_epidata.py errors at build-time because the dependencies in that file aren't installed in the build environment (just setuptools)).

So, this doesn't come with a useful feature, it's just a lateral move to the more modern packaging config.

On the plus side, I learned a lot by reading parts of these guides:

• PyPA Sample Project
• setuptools docs
• PyPA Packaging User Guide

Might be handy in the future when we do #939 and other such changes.

Prerequisites:

• [x] Unless it is a documentation hotfix it should be merged against the dev branch
• [x] Branch is up-to-date with the branch to be merged with, i.e. dev
• [x] Build is successful
• [x] Code is cleaned up and formatted

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[dshemetov]

Good point, thanks! I swapped the commands over to the new ones (sdist and wheel) and added the new build dependency to CI.

Also updated the publish action based on hints from my IDE:

And updated changelog too (I figure we can just keep the changelog dates approximate? Doesn't feel like a big deal if those are one day off).

[melange396]

we can always fix the date on release day