fix: added replacing system-x-critial replacement

- this was added for being able to run the ct install / upgrade behaviour
so that we also can test with that priorityClassName set pods, that normally get a
system-node critial or system-cluster-critical priorityClassName set.
These only will be allowed to run in namespace kube-system and that for
we need to drop the priorityClassName here to null for our tests.

test/e2e-kind.sh

@@ -130,6 +130,12 @@ install_dummylb() {
     echo
 }
 
+replace_priority_class_name_system_x_critical() {
+    echo 'Replacing priorityClassName: system-X-critical'
+    grep -rl "priorityClassName: system-" . | xargs sed -i 's/system-.*-critical/null/g'
+    echo
+}
+
 main() {
     run_ct_container "$1"
     shift
@@ -140,6 +146,7 @@ main() {
     install_tiller
     install_dummylb
     install_certmanager
+    replace_priority_class_name_system_x_critical
 
     docker_exec ct lint-and-install --upgrade --debug "$@"
     echo