try to fix build_wheel_cuml.sh again

ci/build_wheel_cuml.sh

@@ -10,19 +10,11 @@ RAPIDS_PY_CUDA_SUFFIX="$(rapids-wheel-ctk-name-gen ${RAPIDS_CUDA_VERSION})"
 
 # Download the libcuml wheel built in the previous step and make it
 # available for pip to find.
-LIBCUML_WHEELHOUSE=$(RAPIDS_PY_WHEEL_NAME="libcuml_${RAPIDS_PY_CUDA_SUFFIX}" rapids-download-wheels-from-s3 cpp /tmp/libcuml_dist)
+RAPIDS_PY_WHEEL_NAME="libcuml_${RAPIDS_PY_CUDA_SUFFIX}" rapids-download-wheels-from-s3 cpp /tmp/libcuml_dist
 
 # TODO(jameslamb): remove this when https://github.com/rapidsai/raft/pull/2531 is merged
 source ./ci/use_wheels_from_prs.sh
 
-cat >> ./constraints.txt <<EOF
-libcuml-${RAPIDS_PY_CUDA_SUFFIX} @ file://$(echo ${LIBCUML_WHEELHOUSE}/libcuml_*.whl)
-EOF
-
-# Using env variable PIP_CONSTRAINT is necessary to ensure the constraints
-# are used when creating the isolated build environment.
-export PIP_CONSTRAINT="${PWD}/constraints.txt"
-
 rapids-logger "Generating build requirements"
 
 # TODO(jameslamb): remove this when https://github.com/rapidsai/raft/pull/2531 is merged
@@ -39,7 +31,8 @@ rapids-logger "Installing build requirements"
 python -m pip install \
     -v \
     --prefer-binary \
-    -r /tmp/requirements-build.txt
+    -r /tmp/requirements-build.txt \
+    /tmp/libcuml_dist/libcuml_*.whl
 
 # build with '--no-build-isolation', for better sccache hit rate
 # 0 really means "add --no-build-isolation" (ref: https://github.com/pypa/pip/issues/5735)