Ignore loud dask warnings about legacy dataframe implementation (#17137)

This PR ignores loud dask warnings about legacy dask dataframe implementation is going to be soon removed: dask/dask#11437

Note: We only see this error for `DASK_DATAFRAME__QUERY_PLANNING=False` cases, `DASK_DATAFRAME__QUERY_PLANNING=True` are passing fine.

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

Approvers:
  - Bradley Dice (https://github.com/bdice)
  - Peter Andreas Entschev (https://github.com/pentschev)
  - Richard (Rick) Zamora (https://github.com/rjzamora)

URL: #17137

python/dask_cudf/pyproject.toml

@@ -126,5 +126,8 @@ filterwarnings = [
     # https://github.com/dask/partd/blob/main/partd/pandas.py#L198
     "ignore:Passing a BlockManager to DataFrame is deprecated and will raise in a future version. Use public APIs instead.:DeprecationWarning",
     "ignore:String support for `aggregate_files` is experimental. Behavior may change in the future.:FutureWarning:dask",
+    # Dask now loudly throws warnings: https://github.com/dask/dask/pull/11437
+    # When the legacy implementation is removed we can remove this warning and stop running pytests with `DASK_DATAFRAME__QUERY_PLANNING=False`
+    "ignore:The legacy Dask DataFrame implementation is deprecated and will be removed in a future version.*:FutureWarning",
 ]
 xfail_strict = true