sequential tasks: remove deprecation phrasing

Author: oliver-sanders

src/user-guide/writing-workflows/scheduling.rst

@@ -1396,8 +1396,7 @@ Tasks that depend on their own previous-cycle instance can be declared as
        [[graph]]
            T00,T12 = "foo => bar"
 
-However, this feature is deprecated in favour of explicit intercycle triggers
-which expose the associated scheduling behaviour in the graph:
+However, explicit intercycle triggers are generally preferred:
 
 .. code-block:: cylc