[Release Tests] Fixing groupby_benchmark script (#51353)

ray is not in python std lib yet.

Signed-off-by: Alexey Kudinkin <ak@anyscale.com>

Author: alexeykudinkin

release/nightly_tests/dataset/groupby_benchmark.py

@@ -6,8 +6,8 @@
 import ray
 
 from benchmark import Benchmark
-from python.ray.data import DataContext
-from python.ray.data.context import ShuffleStrategy
+from ray.data import DataContext
+from ray.data.context import ShuffleStrategy
 
 
 def parse_args() -> argparse.Namespace: