Add timeout for cudf.pandas pandas tests (#15284)

This PR adds `timeout` for the pytest command so that we can release the GPU resources if we detect a hang. Total suite usually takes 21 mins, I added 30 mins as the timeout.

Authors:
  - GALI PREM SAGAR (https://github.com/galipremsagar)

Approvers:
  - Bradley Dice (https://github.com/bdice)

URL: #15284

python/cudf/cudf/pandas/scripts/run-pandas-tests.sh

@@ -193,7 +193,7 @@ and not test_numpy_ufuncs_basic[nullable_float-arctanh] \
 and not test_numpy_ufuncs_basic[nullable_float-deg2rad] \
 and not test_numpy_ufuncs_basic[nullable_float-rad2deg]"
 
-PANDAS_CI="1" python -m pytest -p cudf.pandas \
+PANDAS_CI="1" timeout 30m python -m pytest -p cudf.pandas \
     -v -m "not single_cpu and not db" \
     -k "not test_overwrite_warns and not test_complex_series_frame_alignment and not test_to_parquet_gcs_new_file and not test_qcut_nat and not test_add and not test_ismethods and $TEST_NUMPY_UFUNCS_BASIC_FLAKY" \
     --import-mode=importlib \