Overriding title in `getModelSchemaRef` causes duplication in OpenAPI schema

Steps to reproduce

Define a controller with getModelSchemaRef(SomeModel, {title: 'TitleOverride'}).

export class UserController {
  @post('/users', {
    security: OPERATION_SECURITY_SPEC,
    responses: {
      '200': {
        description: 'User',
        content: {
          'application/json': {
            schema: {
              'x-ts-type': User,
            },
          },
        },
      },
    },
  })
  async create(
    @requestBody({
      content: {
        'application/json': {
          schema: getModelSchemaRef(NewUserRequest, {
            title: 'NewUser',
          }),
        },
      },
    })
    newUserRequest: NewUserRequest,
  ): Promise<User> {
    // implementation
  }
}

Current Behavior

The controller above emits schema definitions for both NewUserRequest and NewUser. While NewUserRequest is not referenced anywhere else in the schema.

Expected Behavior

Only NewUser is present in OpenAPI schema.

Additional information

@loopback/repository-json-schema@2.4.2
@loopback/openapi-v3@3.4.1

I presume NewUserRequest is generated from getModelSchemaRef as it should while NewUser comes from parsing paramTypes where it causes a cache miss due to overridden title.

A probable fix could exclude a parameter corresponding to requestBody from enumeration here

https://github.com/strongloop/loopback-next/blob/7f8d8356946dc236dd4daecbfae12e0a0662cf1c/packages/openapi-v3/src/controller-spec.ts#L329

Acceptance Criteria

• Don't generate unused schema for parameter decorated with @requestBody

A solution I can think of is:
https://github.com/strongloop/loopback-next/blob/7f8d8356946dc236dd4daecbfae12e0a0662cf1c/packages/openapi-v3/src/controller-spec.ts#L329

should search through the content objects in the request body spec, if all contents' schemas exist in reference, then skip generating the one inferred from model ctor.

Commencez dans packages/openapi-v3/src/controller-spec.ts, autour de l’énumération de paramètres référencée, et suivez comment les schémas de requestBody et les constructeurs de modèles inférés arrivent dans les composants OpenAPI. Reproduisez le cas de surcharge de title, puis vérifiez qu’un corps de requête dont le schéma est déjà référencé ne génère pas de schéma dupliqué inutilisé.