deps: update undici to 7.15.0

[nodejs-github-bot]

This is an automated update of undici to 7.15.0.

[nodejs-github-bot]

Review requested:

• @nodejs/security-wg

[richardlau]

See #59605

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.27%. Comparing base (d58343e) to head (a9f7559).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #59827   +/-   ##
=======================================
  Coverage   88.26%   88.27%           
=======================================
  Files         701      701           
  Lines      206784   206784           
  Branches    39762    39766    +4     
=======================================
+ Hits       182528   182530    +2     
+ Misses      16304    16253   -51     
- Partials     7952     8001   +49     

see 45 files with indirect coverage changes

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