Add Idempotent IT cases for vrrp, vrf, vtp (#28895)

test/integration/targets/nxos_vtp_version/tests/common/sanity.yaml

@@ -9,9 +9,22 @@
       provider: "{{ connection }}"
 
   - name: configure vtp version
-    nxos_vtp_version:
+    nxos_vtp_version: &configure
       version: 2
       provider: "{{ connection }}"
+    register: result
+
+  - assert: &true
+      that:
+        - "result.changed == true"
+  
+  - name: "Conf Idempotence"
+    nxos_vtp_version: *configure
+    register: result
+
+  - assert: &false
+      that:
+        - "result.changed == false"
 
   always:
   - name: disable feature vtp