Mitigate flaky GPU test. (#8078)
Mitigate flaky GPU test. (#8078)

The flakiness is caused by the global random engine, which will take some time to fix.
dmlc/xgboost,dmlc/xgboost,dmlc/xgboost,dmlc/xgboost,dmlc/xgboost,dmlc/xgboost