update pyproject.toml to follow new license format so builds are supported after Feb. 18th

[jackmisbach]

#16 10.05       [stderr]
#16 10.05       /root/.cache/uv/builds-v0/.tmpGUmIWv/lib/python3.14/site-packages/setuptools/config/_apply_pyprojecttoml.py:82:
#16 10.05       SetuptoolsDeprecationWarning: `project.license` as a TOML table is
#16 10.05       deprecated
#16 10.05       !!
#16 10.05 
#16 10.05       
#16 10.05       ********************************************************************************
#16 10.05               Please use a simple string containing a SPDX expression for
#16 10.05       `project.license`. You can also use `project.license-files`. (Both
#16 10.05       options available on setuptools>=77.0.0).
#16 10.05 
#16 10.05               By 2026-Feb-18, you need to update your project and remove
#16 10.05       deprecated calls
#16 10.05               or your builds will no longer be supported.
#16 10.05 
#16 10.05               See
#16 10.05       https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license
#16 10.05       for details.
#16 10.05       
#16 10.05       ********************************************************************************

https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.59%. Comparing base (029cfe8) to head (b768f0e).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1337      +/-   ##
==========================================
+ Coverage   86.53%   86.59%   +0.05%     
==========================================
  Files         113      113              
  Lines       10496    10496              
  Branches     4029     4029              
==========================================
+ Hits         9083     9089       +6     
+ Misses        814      807       -7     
- Partials      599      600       +1     

see 2 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.