Fix tests with GeoUtils data.setter and __array_interface__ update

[rhugonnet]

Updating a couple tests that used syntax only supported by the previous __array_interface__ or raised UserWarning due to the new data.setter of Raster.
Will make CI pass once GlacioHack/geoutils#302 is merged.

[rhugonnet]

I finally found the source of the errors (it's been 2 weeks)! Parallelized tests run automatically with pytest-xdist, and this started impacting Raster reading/writing (maybe because of some issue in a low-level dependency).
The issue for tracking this, is that the effect was that sometimes (randomly) the grid was read as full of nodata.

Locally, we rarely run with pytest -n=auto, which is why we could not reproduce it. Here's the fix: 0a59b42

Added a comment and closed: GlacioHack/geoutils#293 (comment). In the end, this is not related to floating nodata at all...

[rhugonnet]

Merging this, as only 2 lines have changed: the pytest-xdist fix + the commit hash for the new xdem-data with nodata changed to -9999. We can decide later if we keep this new -9999, or revert to the floating nodata.