chore!: remove usingPromise

[mroderick]

Everyone should be using native promises by now, or should know how to stub natives

How to verify - mandatory

1. Check out this branch
2. npm install
3. npm test

Checklist for author

• npm run lint passes
• References to standard library functions are cached.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.82%. Comparing base (95d4b8f) to head (d4e77e0).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2644      +/-   ##
==========================================
- Coverage   96.05%   95.82%   -0.24%     
==========================================
  Files          40       39       -1     
  Lines        1926     1891      -35     
==========================================
- Hits         1850     1812      -38     
- Misses         76       79       +3     

Flag	Coverage Δ
unit	95.82% <100.00%> (-0.24%)	⬇️

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[fatso83]

seems legit.

All cases I could find just used the default Promise implementation anyway, when using this function.

https://github.com/search?q=.usingPromise+%28language%3AJavaScript+OR+language%3ATypeScript+%29+-path%3Alib%2Fsinon%2F*.js&type=code

[mroderick]

This has been published to the npm registry as part of sinon@20.0.0