Extract new enum out of response file

The new guidelines make it clear that we should not add new types in request or
response files.

Author: pquentin

output/openapi/elasticsearch-openapi.json

@@ -116,3 +116,8 @@ export enum ApiKeyType {
   rest,
   cross_cluster
 }
+
+export enum ApiKeyManagedBy {
+  cloud,
+  elasticsearch
+}

output/openapi/elasticsearch-serverless-openapi.json

@@ -18,6 +18,7 @@
  */
 
 import { Id, Metadata, Name, Username } from '@_types/common'
+import { ApiKeyManagedBy } from '@security/_types/ApiKey'
 import { RealmInfo } from '@security/_types/RealmInfo'
 import { Token } from './types'
 
@@ -44,11 +45,6 @@ export class Response {
 export class AuthenticateApiKey {
   id: Id
   name?: Name
-  managed_by: AuthenticateApiKeyManagedBy
+  managed_by: ApiKeyManagedBy
   internal: boolean
 }
-
-export enum AuthenticateApiKeyManagedBy {
-  cloud,
-  elasticsearch
-}