change xarray version requirement

[raphaeldussin]

xESMF is not compatible with version 0.16.1. Rather than restrain to older versions, this ensure 0.16.1 is skipped and allows ulterior versions (compatible)

Checklist

• [x] Used a personal fork of the feedstock to propose changes
• [ ] Bumped the build number (if the version is unchanged)
• [ ] Reset the build number to 0 (if the version changed)
• [ ] Re-rendered with the latest conda-smithy (Use the phrase code>@<space/conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• [ ] Ensured the license file is being packaged.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[ocefpaf]

Thanks, this would need a build number bump but we should also discuss if a new release that frees the pin is needed. Let's move it to #12.