TST: failing to load pyart

[neutrinoceros]

The test pipeline on Jenkins appears to be broken as an ImportError is raised when trying to lazy-load pyart

https://tests.yt-project.org/job/yt_py310_git/8571/

I have reported the problem upstream ARM-DOE/pyart#1680
In the meantime we can add datatree as an optional requirement on our side as a temporary measure.

[kmuehlbauer]

@neutrinoceros Heads-up, datatree was merged into xarray codebase recently.

To use xarray-datatree (as in the test) you would also need to pin xarray to <=2024.9.0 and xradar <=to 0.7.0.

xradar 0.7.0 has a pin for xarray <= 2024.9.0, uses old datatree from xarray-contrib/datatree
xradar 0.8.0 has a pin for xarray >= 2024.10.0, uses new datatree from xarray codebase

HTH

[neutrinoceros]

marking this as a blocker since we cannot merge anything until there's at least a workaround for this issue

[chrishavlin]

I can take a look at modifying the deps on the yt side to get tests to pass.

[neutrinoceros]

fixed in #5042