test_runner: remove failure attribute in junit_report testcase element

[devholic22]

Fixes: #59593

This PR aligns the Node.js test runner’s JUnit XML output with the official JUnit specification by removing the non-standard failure attribute from elements and replacing it with a proper nested tag.

Changes

• Remove non-compliant failure attribute from elements
• Update snapshot tests accordingly

Background

The JUnit XML specification mandates that failure details must be represented via a nested (child) <failure> element inside a <testcase>, rather than as an attribute.

However, the Node.js test runner previously:
• Incorrectly embedded the failure message as a failure="..." attribute on , which is not spec-compliant
• This caused compatibility issues with tools like GitLab, Jenkins, or any CI/CD pipeline that parses JUnit reports strictly

Before:

<testcase name="testName" time="0.002234" classname="test" failure="The value must be 01 !== 0">
  <failure type="testCodeFailure" message="The value must be 01 !== 0">

After:

<testcase name="testName" time="0.002234" classname="test">
    <failure type="testCodeFailure" message="The value must be 01 !== 0">

Testing

• All existing tests pass

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[jasnell]

While the change the good, I wonder if we have to treat this as potentially breaking? @nodejs/test_runner @nodejs/tsc any thoughts? I'm fine landing as a semver-patch but want to be sure.

[MoLow]

LGTM. also not sure rgarding semver-major vs patch

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/68991/

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.87%. Comparing base (bcb802c) to head (dc807aa).
⚠️ Report is 29 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #59685      +/-   ##
==========================================
- Coverage   89.91%   89.87%   -0.04%     
==========================================
  Files         667      667              
  Lines      196600   196855     +255     
  Branches    38601    38646      +45     
==========================================
+ Hits       176780   176933     +153     
- Misses      12269    12359      +90     
- Partials     7551     7563      +12     

Files with missing lines	Coverage Δ
lib/internal/test_runner/reporter/junit.js	94.96% <ø> (+0.59%)	⬆️

... and 41 files with indirect coverage changes

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