[BUG] [typescript-redux-query] index.ts overwrites file generated from type named Index

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?

Description

If I have a type named Index, the generated index.ts overwrites Index.ts generated from the type.

openapi-generator version

4.3.0

OpenAPI declaration file content or url

openapi: '3.0.0'
info:
  version: 0.0.0
  title: Bug
paths:
  /bug:
    get:
      responses:
        default:
          $ref: '#/components/responses/Response'
components:
  responses:
    Response:
      description: response
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Index'
  schemas:
    Index:
      type: string
      enum:
        - foo
        - bar

Command line used for generation

openapi-generator generate -i bug.yaml -g typescript-redux-query -o bug/

Steps to reproduce

• Generate code with the above command line
• Check the generated code with tsc bug/src/index.ts
• You get

bug/src/apis/DefaultApi.ts:19:5 - error TS2305: Module '"../../../../../../Users/thsoft/Temp/bug/src/models"' has no exported member 'Index'.

19     Index,
       ~~~~~

because models/Index.ts was overwritten by models/index.ts.

Related issues/PRs

I found none.

Suggest a fix

There could be two alternatives:

• Rename models/Index.ts since the file name is arbitrary.
• Generate no index.ts since it is just a convention (maybe could be disabled by a generator option).

Reproduce the issue with the provided OpenAPI declaration and the typescript-redux-query command, then inspect how generated models/Index.ts and models/index.ts are produced. Verify the fix by running tsc bug/src/index.ts and confirming the generated Index export is preserved without overwriting.