Update docs: ESQL CCS no longer preview (#130022)

Author: smalyshev

docs/reference/esql/esql-across-clusters.asciidoc

@@ -6,8 +6,6 @@
 
 [partintro]
 
-preview::["{ccs-cap} for {esql} is in technical preview and may be changed or removed in a future release. Elastic will work to fix any issues, but features in technical preview are not subject to the support SLA of official GA features."]
-
 [NOTE]
 ====
 For {ccs-cap} with {esql} on version 8.16 or later, remote clusters must also be on version 8.16 or later.

docs/reference/search/search-your-data/search-across-clusters.asciidoc

@@ -22,7 +22,7 @@ The following APIs support {ccs}:
 * experimental:[] <<eql-search-api,EQL search>>
 * experimental:[] <<sql-search-api,SQL search>>
 * experimental:[] <<search-vector-tile-api,Vector tile search>>
-* experimental:[] <<esql-cross-clusters,ES|QL>>
+* <<esql-cross-clusters,ES|QL>>
 
 [discrete]
 === Prerequisites