test_runner: preserve signal-based interruption exit codes

[ace-tk]

Summary

• preserve signal-based exit semantics when test runner is interrupted
• set SIGINT/SIGTERM derived exit codes (130/143)
• update test-runner-exit-code coverage for both signals

Test plan

• python3 tools/test.py test/parallel/test-runner-exit-code.js

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[codecov]

Codecov Report

❌ Patch coverage is 88.88889% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 89.68%. Comparing base (69fdff9) to head (83c163f).
⚠️ Report is 29 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/test_runner/harness.js	88.88%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #62359      +/-   ##
==========================================
+ Coverage   89.67%   89.68%   +0.01%     
==========================================
  Files         676      676              
  Lines      206693   206697       +4     
  Branches    39576    39582       +6     
==========================================
+ Hits       185346   185376      +30     
+ Misses      13482    13460      -22     
+ Partials     7865     7861       -4     

Files with missing lines	Coverage Δ
lib/internal/test_runner/harness.js	87.02% <88.88%> (-0.11%)	⬇️

... and 54 files with indirect coverage changes

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[atlowChemi]

@ace-tk could you take a look? the tests failing are related to the changes