Add Junix XML export for SuiteResult

[Mapalo90]

Description

Adds native JUnit XML export for SuiteResult using only xml.etree.ElementTree.

This PR introduces:

• giskard.checks.export.junit.to_junit_xml
• SuiteResult.to_junit_xml(...) convenience method
• JUnit XML mapping aligned with maintainer feedback:
  • SuiteResult -> <testsuite>
  • ScenarioResult -> <testcase>
• scenario-level assertion counts
• final_trace and step payloads as properties
• metrics as JUnit properties
• failure / error / skipped mapping at the scenario level
• timing information
• tests for XML structure, file output, metrics, and convenience method

Validation:

• uv run pytest libs/giskard-checks/tests/export/test_junit.py -q
• uv run pytest libs/giskard-checks/tests -q

Related Issue

Closes #2345

Type of Change

• 📚 Examples / docs / tutorials / dependencies update
• 🔧 Bug fix (non-breaking change which fixes an issue)
• 🥂 Improvement (non-breaking change which improves an existing feature)
• 🚀 New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 🔐 Security fix

Checklist

• I've read the CODE_OF_CONDUCT.md document.
• I've read the CONTRIBUTING.md guide.
• I've written tests for all new methods and classes that I created.
• I've written the docstring in Google format for all the methods and classes that I used.
• I've updated the pdm.lock running pdm update-lock (only applicable when pyproject.toml has been
  modified)

[gemini-code-assist]

Code Review

This pull request introduces the ability to export test suite results to JUnit XML format, adding a to_junit_xml method to the SuiteResult class and implementing the export logic in a new module. The implementation includes detailed mapping of scenario results, checks, and metrics to standard JUnit elements. Review feedback identifies opportunities to improve the generated XML by removing redundant step data in failure details and reducing file size by avoiding duplicate JSON payloads across the properties and system-out sections.

[Mapalo90]

Updated the XML mapping to follow maintainer feedback: SuiteResult now maps to a single <testsuite> and each ScenarioResult maps to a <testcase>.

[Mapalo90]

I addressed the review feedback in f7492a6 by removing duplicated payloads from failure details/system-out while keeping the structured data in <properties>. Local validation still passes:

• uv run pytest libs/giskard-checks/tests/export/test_junit.py -q
• uv run pytest libs/giskard-checks/tests -q

When convenient, could a maintainer add the safe for build label so the required workflows can run?

[kevinmessiaen]

Thanks for your first contribution to Giskard!

Looking good, however there is a small issue with having duplicated data in the report.

I also left some comments on how we could improve the outputs display while reusing already existing code.

[kevinmessiaen]

from __future__ import annotations is unnecessary with 3.12+

Suggested change

from __future__ import annotations

[Mapalo90]

Hi again, thanks for the feedback. I pushed 16ec1b4, which removes the __future__ imports, drops the TestCaseResult alias and switches system-out to the existing rich scenario report output. Local tests still pass. When you have a moment, could you take another look?

[kevinmessiaen]

This looks good to me. Thanks for the quick changes!

The CI is failing because of the linter, you can fix it with make format