Adds tech preview tag to the 'Create an Elasticsearch inference' endpoint's parameters (#5684)

* Adds tech preview callout

* Adds tech preview tags

* Removes sentence

* Adds serverless tech preview tag

(cherry picked from commit 4a876c0)

Author: kosabogi

specification/inference/_types/CommonTypes.ts

@@ -1339,12 +1339,16 @@ export class ElasticsearchServiceSettings {
    *
    * When `long_document_strategy` is set to `chunk`, Elasticsearch splits each document into smaller parts but still returns a single score per document.
    * That score reflects the highest relevance score among all chunks.
+   * @availability stack stability=experimental visibility=public
+   * @availability serverless stability=experimental visibility=public
    */
   long_document_strategy?: string
   /**
    * Only for the `rerank` task type.
    * Limits the number of chunks per document that are sent for inference when chunking is enabled.
    * If not set, all chunks generated for the document are processed.
+   * @availability stack stability=experimental visibility=public
+   * @availability serverless stability=experimental visibility=public
    */
   max_chunks_per_doc?: integer
 }