chore: skpkg with no manual edit

[stevenhua0320]

@sbillinge ready to review. I have rescikit-packaged it. I maintained all the license info as before. Moreover, I cleaned the duplicated workflow and edit the README.rst badge link to make it consistent with the workflow. I have also tested locally and the documentation still renders correctly.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.78%. Comparing base (459f899) to head (609db53).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #93   +/-   ##
=======================================
  Coverage   93.78%   93.78%           
=======================================
  Files           4        4           
  Lines         177      177           
=======================================
  Hits          166      166           
  Misses         11       11           

🚀 New features to boost your workflow:

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

[sbillinge]

Looks good. Please see comments. Also make sure the duplicate code of conduct file is deleted and any duplicate workflows like matrix on merge to main

[sbillinge]

This should stay as true

[sbillinge]

Check if these are still needed. Good if they are not needed but presumably they were added before for done reason

[sbillinge]

Please leave all these statements as they were before.

[sbillinge]

Please use your new way of doing the copyright

[sbillinge]

i.e., 2026 - present, diffpy.fourigui contributors and change it everywhere.

Please could you check that scikit package does it this way and make and issue over there if not? Thanks.