Do not build CUDA libs in Python jobs (#2039)

This PR should prevent building CUDA libs in Python jobs and speed up CI

Authors:
  - Jordan Jacobelli (https://github.com/Ethyling)

Approvers:
  - AJ Schmidt (https://github.com/ajschmidt8)

URL: #2039

ci/cpu/build.sh

@@ -69,8 +69,15 @@ conda config --set ssl_verify False
 # machine with a single CUDA version, then have the gpu/build.sh script simply
 # install. This should eliminate a mismatch between different CUDA versions on
 # cpu vs. gpu builds that is problematic with CUDA 11.5 Enhanced Compat.
-BUILD_LIBCUGRAPH=1
-BUILD_CUGRAPH=1
+if [ "$BUILD_LIBCUGRAPH" == '1' ]; then
+  BUILD_CUGRAPH=1
+  # If we are doing CUDA + Python builds, libcugraph package is located at ${CONDA_BLD_DIR}
+  CONDA_LOCAL_CHANNEL="${CONDA_BLD_DIR}"
+else
+  # If we are doing Python builds only, libcugraph package is placed here by Project Flash
+  CONDA_LOCAL_CHANNEL="ci/artifacts/cugraph/cpu/.conda-bld/"
+fi
+
 
 ###############################################################################
 # BUILD - Conda package builds
@@ -97,8 +104,8 @@ if [ "$BUILD_CUGRAPH" == "1" ]; then
     gpuci_conda_retry build --no-build-id --croot ${CONDA_BLD_DIR} conda/recipes/pylibcugraph --python=$PYTHON
     gpuci_conda_retry build --no-build-id --croot ${CONDA_BLD_DIR} conda/recipes/cugraph --python=$PYTHON
   else
-    gpuci_conda_retry build --no-build-id --croot ${CONDA_BLD_DIR} conda/recipes/pylibcugraph -c $CONDA_BLD_DIR --dirty --no-remove-work-dir --python=$PYTHON
-    gpuci_conda_retry build --no-build-id --croot ${CONDA_BLD_DIR} conda/recipes/cugraph -c $CONDA_BLD_DIR --dirty --no-remove-work-dir --python=$PYTHON
+    gpuci_conda_retry build --no-build-id --croot ${CONDA_BLD_DIR} conda/recipes/pylibcugraph -c ${CONDA_LOCAL_CHANNEL} --dirty --no-remove-work-dir --python=$PYTHON
+    gpuci_conda_retry build --no-build-id --croot ${CONDA_BLD_DIR} conda/recipes/cugraph -c ${CONDA_LOCAL_CHANNEL} --dirty --no-remove-work-dir --python=$PYTHON
     mkdir -p ${CONDA_BLD_DIR}/cugraph
     mv ${CONDA_BLD_DIR}/work ${CONDA_BLD_DIR}/cugraph/work
   fi