Update h5grove snapshot following fix for complex256 numbers

[axelboc]

Following silx-kit/h5grove#91, h5grove no longer responds with 500 errors when fetching complex256 datasets. I've upgraded h5grove on Bosquet, so I'm now updating the test snapshots here.

Note that h5grove also no longer casts the float32 real/imag parts of complex64 numbers to float64 when serializing to JSON.

We still have the issue that any float128 number that overflows the float64 range is cast to inf and serialised to JSON as null (cf. #641), which breaks the visualizations. The best way around this would be to fetch complex numbers as binary, but that's a problem for another day.