[CI] Functional: Increase Ulimit to 4096

Functional tests started to fail with
"Too many open files" randomly, the default ulimit in
OS is configured to 1024, increasing this to 4096
to avoid these random failures.

Closes-Bug: #2080199
Change-Id: Iff86599678ebdd5189d5b56d11f3373c9b138562

roles/configure_functional_tests/tasks/main.yaml

@@ -47,6 +47,10 @@
         fi
 
         configure_host_for_func_testing
+        echo "$USER soft nofile 4096" | sudo tee /etc/security/limits.d/99-user.conf
 
     executable: /bin/bash
   environment: "{{ override_env | default({})}}"
+
+- name: Reset ssh connection to pick up limits
+  meta: reset_connection