[tests][dask] add missing compute() in Dask test (#4412)
[tests][dask] add missing compute() in Dask test (#4412)


henry0312/LightGBM,henry0312/LightGBM,microsoft/LightGBM,microsoft/LightGBM,microsoft/LightGBM,microsoft/LightGBM,henry0312/LightGBM,henry0312/LightGBM,microsoft/LightGBM,henry0312/LightGBM