docs(openapi): amend response description for file deletion (#573)

Author: giuseppe-steduto

docs/openapi.json

@@ -1453,7 +1453,7 @@
         ],
         "responses": {
           "200": {
-            "description": "Requests succeeded. The file has been downloaded.",
+            "description": "Request succeeded. Details about deleted files and failed deletions are returned.",
             "schema": {
               "type": "file"
             }

reana_workflow_controller/rest/workflows_workspace.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 #
 # This file is part of REANA.
-# Copyright (C) 2020, 2021, 2022 CERN.
+# Copyright (C) 2020, 2021, 2022, 2024 CERN.
 #
 # REANA is free software; you can redistribute it and/or modify it
 # under the terms of the MIT License; see LICENSE file for more details.
@@ -315,7 +315,7 @@ def delete_file(workflow_id_or_name, file_name):  # noqa
       responses:
         200:
           description: >-
-            Requests succeeded. The file has been downloaded.
+            Request succeeded. Details about deleted files and failed deletions are returned.
           schema:
             type: file
         404: