Use libcudf wheel from PR rather than nightly for polars-polars C…

…I test job (#16975)

This PR fixes an issue where one `cudf-polars` CI job uses the `pylibcudf` wheel generated from the branch being tested, but pulls a libcudf nightly which can cause issues when introducing cython/c++ changes simultaneously.

Authors:
  - https://github.com/brandon-b-miller

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

URL: #16975

ci/test_cudf_polars_polars_tests.sh

@@ -24,14 +24,17 @@ rapids-logger "Download wheels"
 RAPIDS_PY_CUDA_SUFFIX="$(rapids-wheel-ctk-name-gen ${RAPIDS_CUDA_VERSION})"
 RAPIDS_PY_WHEEL_NAME="cudf_polars_${RAPIDS_PY_CUDA_SUFFIX}" RAPIDS_PY_WHEEL_PURE="1" rapids-download-wheels-from-s3 ./dist
 
-# Download the pylibcudf built in the previous step
-RAPIDS_PY_WHEEL_NAME="pylibcudf_${RAPIDS_PY_CUDA_SUFFIX}" rapids-download-wheels-from-s3 ./local-pylibcudf-dep
+# Download libcudf and pylibcudf built in the previous step
+RAPIDS_PY_WHEEL_NAME="libcudf_${RAPIDS_PY_CUDA_SUFFIX}" rapids-download-wheels-from-s3 cpp ./local-libcudf-dep
+RAPIDS_PY_WHEEL_NAME="pylibcudf_${RAPIDS_PY_CUDA_SUFFIX}" rapids-download-wheels-from-s3 python ./local-pylibcudf-dep
 
-rapids-logger "Install pylibcudf"
-python -m pip install ./local-pylibcudf-dep/pylibcudf*.whl
+rapids-logger "Install libcudf, pylibcudf and cudf_polars"
+python -m pip install \
+    -v \
+    "$(echo ./dist/cudf_polars_${RAPIDS_PY_CUDA_SUFFIX}*.whl)[test]" \
+    "$(echo ./local-libcudf-dep/libcudf_${RAPIDS_PY_CUDA_SUFFIX}*.whl)" \
+    "$(echo ./local-pylibcudf-dep/pylibcudf_${RAPIDS_PY_CUDA_SUFFIX}*.whl)"
 
-rapids-logger "Install cudf_polars"
-python -m pip install $(echo ./dist/cudf_polars*.whl)
 
 TAG=$(python -c 'import polars; print(f"py-{polars.__version__}")')
 rapids-logger "Clone polars to ${TAG}"