[BUG] [spring] [server] 5.0.1 unused imports in generated interfaces

Created by: lfischer

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Generated API interfaces contain the following unused imports, which introduce unnecessary dependencies:

• import org.springframework.data.domain.Pageable;
• import springfox.documentation.annotations.ApiIgnore;

openapi-generator version

5.0.1

OpenAPI declaration file content or url

https://raw.githubusercontent.com/openapitools/openapi-generator/master/modules/openapi-generator/src/test/resources/3_0/petstore.yaml

Generation Details

Steps to reproduce

file "springboot-options.json"

{
"basePackage":"io.swagger",
"configPackage":"io.swagger.config",
"parentGroupId":"org.springframework.boot",
"parentArtifactId":"spring-boot-starter-parent",
"parentVersion":"2.4.3",
"serverPort":9230,
"dateLibrary":"java8"
}

command line

java -jar ./openapi-generator-cli-5.0.1.jar generate -g spring -i petstore.yaml -o server\springboot\openapi -c springboot-options.json

Example: imports within generated file UserApi

package org.openapitools.api;

import java.util.List;
import org.openapitools.model.User;
import io.swagger.annotations.*;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.annotation.Validated;
import org.springframework.data.domain.Pageable;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.multipart.MultipartFile;
import springfox.documentation.annotations.ApiIgnore;

Related issues/PRs

Suggest a fix

Remove imports of springfox.documentation.annotations.ApiIgnore and data.domain.Pageable within the api interfaces, as they are not used and not needed.