fix: minor correction in end_to_end_tests/openapi.json

Add responses to `end_to_end_tests/openapi.json` where is was empty. Responses should define at least one response

Author: mtovt

end_to_end_tests/openapi.json

@@ -977,7 +977,11 @@
             "in": "query"
           }
         ],
-        "responses": {}
+        "responses": {
+          "200": {
+            "description": ""
+          }
+        }
       }
     },
     "/location/header/types": {
@@ -1020,7 +1024,11 @@
             "in": "header"
           }
         ],
-        "responses": {}
+        "responses": {
+          "200": {
+            "description": ""
+          }
+        }
       }
     },
     "/naming/keywords": {
@@ -1041,7 +1049,11 @@
             "in": "query"
           }
         ],
-        "responses": {}
+        "responses": {
+          "200": {
+            "description": ""
+          }
+        }
       }
     }
   },