[jdotc1]

Install xarray in macOS and Windows Python CI and mark PythonXarrayTest as skipped when xarray is absent. Addresses the CI checks in #6950; 4D wrapping remains a separate follow-up.

Validation

• Parsed all three Python pipeline YAML files and checked xarray installation commands.
• Checked the CTest skip registration and whitespace.
• Full native CTest was unavailable locally (no CMake/Pixi build); pipeline validation is pending.

AI assistance

Automated coding assistance prepared this CI configuration change and ran static checks. CI results and contributor review are required before marking ready.

[greptile-apps]

Confidence Score: 5/5

[Low impact] The PR appears safe to merge.

Summary

Adds xarray to the macOS and Windows Python CI dependency installs.

• macOS and Windows Python CI install xarray and report missing-package skips.

_{Reviews (1) · Last reviewed commit: "STYLE: Format xarray test skip property" · Reviewed by Greptile}