[PR #9191/fa7c2df4 backport][stable-8] ufw: add note to docs about concurrency (#9193)

ufw: add note to docs about concurrency (#9191)

* ufw: add note to docs about concurrency

* wordsmithing

(cherry picked from commit fa7c2df4b8)

Co-authored-by: Alexei Znamensky <103110+russoz@users.noreply.github.com>

plugins/modules/ufw.py

@@ -23,6 +23,10 @@ author:
     - Ahti Kitsik (@ahtik)
 notes:
     - See C(man ufw) for more examples.
+    - >
+      B(Warning:) Whilst the module itself can be run using concurrent strategies, C(ufw) does not support concurrency,
+      as firewall rules are meant to be ordered and parallel executions do not guarantee order.
+      B(Do not use concurrency:) The results are unpredictable and the module may fail silently if you do.
 requirements:
     - C(ufw) package
 extends_documentation_fragment: