deprecating local param from alias req (#3094)

Author: l-trotta

output/openapi/elasticsearch-openapi.json

@@ -62,6 +62,7 @@ export interface Request extends RequestBase {
     /**
      * If `true`, the request retrieves information from the local node only.
      * @server_default false
+     * @deprecated 8.12.0
      */
     local?: boolean
   }

output/openapi/elasticsearch-serverless-openapi.json

@@ -65,6 +65,7 @@ export interface Request extends RequestBase {
     /**
      * If `true`, the request retrieves information from the local node only.
      * @server_default false
+     * @deprecated 8.12.0
      */
     local?: boolean
   }