Add deprecation warning for ELSER in semantic search tutorial

Added a deprecation warning to the “Tutorial: semantic search with semantic_text” to inform users that the elser service is deprecated as of version 8.16 and will be removed in a future release. The warning advises users to use the Elasticsearch inference service with model_id in service_settings instead. This update aligns the tutorial with the existing deprecation notice on the ELSER documentation page, ensuring clarity for users following the tutorial.

Author: eshaffer321

docs/reference/search/search-your-data/semantic-search-semantic-text.asciidoc

@@ -6,6 +6,13 @@
 
 beta[]
 
+[WARNING]
+.Deprecated in 8.16
+====
+The elser service is deprecated and will be removed in a future release. 
+Use the <<infer-service-elasticsearch>> instead, with model_id included in the service_settings.
+====
+
 This tutorial shows you how to use the semantic text feature to perform semantic search on your data.
 
 Semantic text simplifies the {infer} workflow by providing {infer} at ingestion time and sensible default values automatically.
@@ -282,4 +289,4 @@ query from the `semantic-embedding` index:
 
 * If you want to use `semantic_text` in hybrid search, refer to https://colab.research.google.com/github/elastic/elasticsearch-labs/blob/main/notebooks/search/09-semantic-text.ipynb[this notebook] for a step-by-step guide.
 * For more information on how to optimize your ELSER endpoints, refer to {ml-docs}/ml-nlp-elser.html#elser-recommendations[the ELSER recommendations] section in the model documentation.
-* To learn more about model autoscaling, refer to the {ml-docs}/ml-nlp-auto-scale.html[trained model autoscaling] page.
+* To learn more about model autoscaling, refer to the {ml-docs}/ml-nlp-auto-scale.html[trained model autoscaling] page.