Apply suggestion from @StanFromIreland

Co-authored-by: Stan Ulbrych <stan@python.org>

Author: serhiy-storchaka

Doc/library/re.rst

@@ -881,7 +881,7 @@ Flags
       no longer depend on the locale at compile time.
       Only the locale at matching time affects the result of matching.
 
-   .. deprecated:: next
+   .. deprecated-removed:: next 3.18
       The flag and the inline flag ``(?L)`` are deprecated.
       Decode the input and match str patterns instead.