Pin torch version in cugraph-dgl wheel test (#4447)

To fix the [CI nightly issue](https://github.com/rapidsai/cugraph/actions/runs/9188624604/job/25298484338#step:8:837) in cugraph-dgl wheel test for CUDA 11.

Authors:
  - Tingyu Wang (https://github.com/tingyu66)

Approvers:
  - Rick Ratzel (https://github.com/rlratzel)
  - Brad Rees (https://github.com/BradReesWork)
  - Jake Awe (https://github.com/AyodeAwe)

URL: #4447

ci/test_wheel_cugraph-dgl.sh

@@ -32,8 +32,18 @@ fi
 PYTORCH_URL="https://download.pytorch.org/whl/cu${PYTORCH_CUDA_VER}"
 DGL_URL="https://data.dgl.ai/wheels/cu${PYTORCH_CUDA_VER}/repo.html"
 
+# Starting from 2.2, PyTorch wheels depend on nvidia-nccl-cuxx>=2.19 wheel and
+# dynamically link to NCCL. RAPIDS CUDA 11 CI images have an older NCCL version that
+# might shadow the newer NCCL required by PyTorch during import (when importing
+# `cupy` before `torch`).
+if [[ "${NCCL_VERSION}" < "2.19" ]]; then
+  PYTORCH_VER="2.1.0"
+else
+  PYTORCH_VER="2.3.0"
+fi
+
 rapids-logger "Installing PyTorch and DGL"
-rapids-retry python -m pip install torch --index-url ${PYTORCH_URL}
+rapids-retry python -m pip install "torch==${PYTORCH_VER}" --index-url ${PYTORCH_URL}
 rapids-retry python -m pip install dgl==2.0.0 --find-links ${DGL_URL}
 
 python -m pytest python/cugraph-dgl/tests