Add more XXX to the mktemp command in release_test.sh

scripts/release_test.sh

@@ -8,7 +8,7 @@ set -ex
 . $(conda info --base)/etc/profile.d/conda.sh
 
 JLAB_TEST_ENV="${CONDA_DEFAULT_ENV}_test"
-TEST_DIR=$(mktemp -d -t $JLAB_TEST_ENV)
+TEST_DIR=$(mktemp -d -t ${JLAB_TEST_ENV}XXXXX)
 
 conda create --override-channels --strict-channel-priority -c conda-forge -c anaconda -y -n "$JLAB_TEST_ENV" notebook nodejs twine
 conda activate "$JLAB_TEST_ENV"