Remove unsupported stored_fields from get_source API (#4786) (#4823)

(cherry picked from commit f7c9703)

# Conflicts:
#	output/schema/validation-errors.json

Author: pquentin

output/openapi/elasticsearch-openapi.json

@@ -44,12 +44,6 @@
       ],
       "response": []
     },
-    "get_source": {
-      "request": [
-        "Request: query parameter 'stored_fields' does not exist in the json spec"
-      ],
-      "response": []
-    },
     "msearch": {
       "request": [
         "Request: query parameter 'allow_no_indices' does not exist in the json spec",

output/openapi/elasticsearch-serverless-openapi.json

@@ -99,10 +99,6 @@ export interface Request extends RequestBase {
      * A comma-separated list of source fields to include in the response.
      */
     _source_includes?: Fields
-    /**
-     * A comma-separated list of stored fields to return as part of a hit.
-     */
-    stored_fields?: Fields
     /**
      * The version number for concurrency control.
      * It must match the current version of the document for the request to succeed.