Avoid Matplotlib 3.11 vert deprecation in permutation importance plots

[Copilot]

Permutation-importance model card tests were tripping MatplotlibDeprecationWarning (vert deprecated in Matplotlib 3.11), which breaks warning-strict downstream builds. This PR updates our matplotlib compatibility shim to stop forwarding deprecated args on newer matplotlib while preserving behavior on older versions.

• Compatibility layer update (skops.utils._fixes.boxplot)

  • Normalize legacy vert input into orientation when provided.
  • Strip vert from kwargs before calling ax.boxplot on matplotlib versions that support orientation.
  • Keep old-version fallback behavior by still emitting vert only when required.

• Focused regression coverage

  • Add unit tests in skops/utils/tests/test_fixes.py for both version paths:
    • New matplotlib: assert vert is not passed through.
    • Old matplotlib: assert vert is still passed as expected.

• Behavioral effect

  • The permutation-importance plotting path continues to use the same API from Card.add_permutation_importances, but no longer triggers the vert deprecation warning on modern matplotlib.

# before calling matplotlib:
vert = kwargs.pop("vert", None)
if vert is not None and orientation == "vertical":
    orientation = "vertical" if vert else "horizontal"

if parse(mpl_version) >= parse("3.10"):
    kwargs["orientation"] = orientation
else:
    kwargs["vert"] = orientation == "vertical"

• Fixes matplotlib._api.deprecation.MatplotlibDeprecationWarning: vert: bool was deprecated in Matplotlib 3.11 and will be removed in 3.13. #523

[adrinjalali]

@copilot this seems to be only triggered in tests, so we can simply modify tests and make sure they don't raise warnings.

[Copilot]

@copilot this seems to be only triggered in tests, so we can simply modify tests and make sure they don't raise warnings.

Done in b9672fe. I reverted the runtime compatibility change and updated only the permutation-importance test class to filter the Matplotlib 3.11 vert deprecation warning.

[adrinjalali]

@copilot the filter is the wrong solution, since it will become an actual error soon. The fix needs to completely avoid the warning, not ignore it.

[Copilot]

@copilot the filter is the wrong solution, since it will become an actual error soon. The fix needs to completely avoid the warning, not ignore it.

Addressed in de4e766. I removed the warning filter and restored the runtime fix in skops.utils._fixes.boxplot so vert is normalized and not forwarded on newer Matplotlib, with focused compatibility tests for new/old Matplotlib behavior.

[adrinjalali]

@copilot This is the diff I see now.

[Copilot]

@copilot This is the diff I see now.

...

At PR head (de4e766), those filterwarnings lines are removed. I re-checked the branch against origin/main, and the current diff is only in skops/utils/_fixes.py and skops/utils/tests/test_fixes.py. Please refresh the PR view and make sure it isn’t showing the intermediate b9672fe diff.