[DOCS] Remove ifdefs for rollup refactor

Removes some ifdef conditionals overlooked in #70885. That PR removed
docs for the rollup refactor.

docs/reference/data-rollup-transform.asciidoc

@@ -6,23 +6,10 @@
 
 {es} offers the following methods for manipulating your data:
 
-ifdef::permanently-unreleased-branch[]
-
-* <<xpack-rollup>>
-+
-A rollup aggregates an index's time series data and stores the results in new
-read-only index. For example, you can roll up hourly data into daily or weekly
-summaries.
-
-endif::[]
-ifndef::permanently-unreleased-branch[]
-
 * <<xpack-rollup,Rolling up your historical data>>
 +
 include::rollup/index.asciidoc[tag=rollup-intro]
 
-endif::[]
-
 * <<transforms,Transforming your data>>
 +
 include::transform/transforms.asciidoc[tag=transform-intro]