[CI] Update R version on Linux. (#9835)

tests/buildkite/build-gpu-rpkg.sh

@@ -7,7 +7,9 @@ source tests/buildkite/conftest.sh
 echo "--- Build XGBoost R package with CUDA"
 
 tests/ci_build/ci_build.sh gpu_build_r_centos7 docker \
-  --build-arg CUDA_VERSION_ARG=${CUDA_VERSION} tests/ci_build/build_r_pkg_with_cuda.sh \
+			   --build-arg CUDA_VERSION_ARG=${CUDA_VERSION} \
+			   --build-arg R_VERSION_ARG=${R_VERSION} \
+			   tests/ci_build/build_r_pkg_with_cuda.sh \
   ${BUILDKITE_COMMIT}
 
 if [[ ($is_pull_request == 0) && ($is_release_branch == 1) ]]

tests/buildkite/conftest.sh

@@ -27,6 +27,7 @@ NCCL_VERSION=2.16.5-1
 RAPIDS_VERSION=23.10
 SPARK_VERSION=3.4.0
 JDK_VERSION=8
+R_VERSION=4.3.2
 
 if [[ -z ${BUILDKITE:-} ]]
 then