[CI] Detect architecture when determining node download url

Currently CI is setup to always download the x64 Node.js architecture.
When runing builds on ARM machines we'll want to make sure the
architecture matches the machine.

src/dev/ci_setup/setup_env.sh

@@ -56,7 +56,13 @@ export WORKSPACE="${WORKSPACE:-$PARENT_DIR}"
 nodeVersion="$(cat "$dir/.node-version")"
 nodeDir="$cacheDir/node/$nodeVersion"
 nodeBin="$nodeDir/bin"
-classifier="x64.tar.gz"
+hostArch="$(command uname -m)"
+case "${hostArch}" in
+  x86_64 | amd64) nodeArch="x64" ;;
+  aarch64) nodeArch="arm64" ;;
+  *) nodeArch="${hostArch}" ;;
+esac
+classifier="$nodeArch.tar.gz"
 
 UNAME=$(uname)
 OS="linux"