[BUG] [typescript-axios] Unused imports when using 'withSeparateModelsAndApi'

Created by: Nikos410

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?

Description

Hello! When using the typescript-axios client generator with the additional property withSeparateModelsAndApi unused imports are sometimes created.

openapi-generator version

6.0.1 / master

OpenAPI declaration file content or url

https://gist.github.com/Nikos410/32ab8c734b8f9a50adee138aba623f49

Generation Details

openapi-generator-cli generate -i ./openapi-spec-with-inheritance.json -g typescript-axios --additional-properties=withSeparateModelsAndApi=true --additional-properties=apiPackage=apis --additional-properties=modelPackage=models -o ./generated

Steps to reproduce

Generate the typescript-axios client using the spec and cli command above.
Notice unused import of BranchDto in models/internal-authenticated-user-dto.ts and models/remote-authenticated-user-dto.ts:

[...]

import { AbstractUserDto } from './abstract-user-dto';
import { BranchDto } from './branch-dto';

/**
 * @type RemoteAuthenticatedUserDto
 * @export
 */
export type RemoteAuthenticatedUserDto = AbstractUserDto;

Related issues/PRs

A similar issue was already reported in #3743 (closed) and fixed in #3742 by adding // @ts-ignore

Suggest a fix

Add // @ts-ignore to these imports too

CC @Digirik