[stable-6] Add attributes to oneandone, ovh, and rackspace modules (#6064)

Add attributes to oneandone, ovh, and rackspace modules (#5948)

Add attributes to oneandone, ovh, and rackspace modules.

(cherry picked from commit 6bd131f2fb)

plugins/modules/ovh_ip_loadbalancing_backend.py

@@ -22,6 +22,13 @@ notes:
       key as described into U(https://docs.ovh.com/gb/en/customer/first-steps-with-ovh-api/)
 requirements:
     - ovh >  0.3.5
+extends_documentation_fragment:
+    - community.general.attributes
+attributes:
+    check_mode:
+        support: none
+    diff_mode:
+        support: none
 options:
     name:
         required: true