Set guest_os_with_gui=false when no display manager

Signed-off-by: Qi Zhang <qiz@vmware.com>

linux/utils/check_guest_os_gui.yml

@@ -32,6 +32,15 @@
       ignore_errors: true
       delegate_to: "{{ vm_guest_ip }}"
 
+    # If systemctl status display-manager.service error code is 4, it means
+    # the service doesn't exist, so guest OS doesn't have desktop
+    - name: "Set fact of guest OS having no desktop environment"
+      ansible.builtin.set_fact:
+        guest_os_with_gui: false
+      when: >
+        (display_manager_status.rc is undefined or
+        display_manager_status.rc == 4)
+
     - name: "Set fact of guest OS display manager"
       ansible.builtin.set_fact:
         guest_os_display_manager: |-
@@ -51,7 +60,6 @@
     - guest_os_with_gui | bool
     - guest_os_ansible_distribution != 'Astra Linux (Orel)'
 
-
 - name: "Set fact of guest OS display manager for {{ guest_os_ansible_distribution }}"
   ansible.builtin.set_fact:
     guest_os_display_manager: "fly-dm"