Update availability documentation in GraphExploreRequest (#5336)

* Update availability documentation in GraphExploreRequest

Removed serverless availability stability and visibility information from the documentation.

* Update availability documentation for GraphExploreRequest

Author: georgewallace

specification/graph/explore/GraphExploreRequest.ts

@@ -35,7 +35,7 @@ import { Hop } from '../_types/Hop'
  * @doc_id graph-explore-api
  * @rest_spec_name graph.explore
  * @availability stack stability=stable
- * @availability serverless stability=stable visibility=public
+ * @availability serverless stability=stable visibility=private
  * @ext_doc_id graph
  */
 export interface Request extends RequestBase {