[DOCS] Fix Moving Avg Aggregation deprecated macro for Asciidoctor (#42405)

Author: jrodewig

docs/reference/aggregations/pipeline/movavg-aggregation.asciidoc

@@ -1,9 +1,14 @@
 [[search-aggregations-pipeline-movavg-aggregation]]
 === Moving Average Aggregation
 
+ifdef::asciidoctor[]
+deprecated:[6.4.0, "The Moving Average aggregation has been deprecated in favor of the more general <<search-aggregations-pipeline-movfn-aggregation,Moving Function Aggregation>>.  The new Moving Function aggregation provides all the same functionality as the Moving Average aggregation, but also provides more flexibility."]
+endif::[]
+ifndef::asciidoctor[]
 deprecated[6.4.0, The Moving Average aggregation has been deprecated in favor of the more general
 <<search-aggregations-pipeline-movfn-aggregation,Moving Function Aggregation>>.  The new Moving Function aggregation provides
 all the same functionality as the Moving Average aggregation, but also provides more flexibility.]
+endif::[]
 
 Given an ordered series of data, the Moving Average aggregation will slide a window across the data and emit the average
 value of that window.  For example, given the data `[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]`, we can calculate a simple moving