Use true instead of yes.

tasks/general/acct_mgmt/groups.yml

@@ -1,10 +1,10 @@
 ---
 # Groups that do not come to all distros by default.
 
-- name: General | Account Management | System Groups 
+- name: General | Account Management | System Groups
   group:
     name: "{{ item }}"
-    system: yes
+    system: true
     state: present
   loop:
     - sudo