[AIRFLOW-XXXX] Add -- to rm in install_released_airflow_version (#7548)

Adding this -- after rm -f helps in case when you have some weird
files that have spaces and -W in names.

scripts/ci/in_container/_in_container_utils.sh

@@ -352,7 +352,7 @@ function send_kubernetes_logs_to_file_io() {
 
 function install_released_airflow_version() {
     pip uninstall apache-airflow -y || true
-    find /root/airflow/ -type f -print0 | xargs rm -f
+    find /root/airflow/ -type f -print0 | xargs rm -f --
     if [[ ${1} == "1.10.2" || ${1} == "1.10.1" ]]; then
         export SLUGIFY_USES_TEXT_UNIDECODE=yes
     fi