Update docs environment to avoid Xarray bug

[kafitzgerald]

PR Summary

This PR changes the documentation environment specification file to skip Xarray v2024.11.0 with the colormap specification / seaborn import bug. It intentionally doesn't change other environment specification files or the package requirements since this is a rather narrow bug that only impacts our examples because of how we specify colormaps and not something related to geocat-viz itself or broadly impacting Xarray. For this reason I didn't update the release notes either though I can if that is helpful for internal notes.

Closes #262

PR Checklist

General

• Make an issue if one doesn't already exist
• Link the issue this PR resolves by adding closes #XXX to the PR description where XXX is the number of the issue.
• Add a brief summary of changes to docs/release-notes.rst in a relevant section for the next unreleased release. Possible sections include: Documentation, New Features, Bug Fixes, Internal Changes, Breaking Changes/Deprecated
• Add appropriate labels to this PR
• Make your changes in a forked repository rather than directly in this repo
• Open this PR as a draft if it is not ready for review
• Convert this PR from a draft to a full PR before requesting reviewers
• Passes precommit. To set up on your local, run pre-commit install from the top level of the repository. To manually run pre-commits, use pre-commit run --all-files and re-add any changed files before committing again and pushing.

[jukent]

LGTM!