[BUG][KOTLIN] Multiple tags in YAML input lead to duplicate code generated

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? (Partial)
• 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

Duplicate Kotlin code is generated, which then fails to compile.

openapi-generator version

We use org.openapitools:openapi-generator-gradle-plugin:5.2.0

OpenAPI declaration file content or url

Excerpt from input file:

tags:
  - name: customer
    description: xxx
  - name: customer profile
    description: yyy

as well as

paths:
  /customers:
    post:
      tags:
        - customer
        - customer profile
      summary: zzz
      operationId: createCustomer

Generation Details

The following code is produced

@PostMapping(
            value = ["/customers"],
            produces = ["application/json"]
    )
    fun createCustomer( @RequestHeader(value="requestId", required=true) requestId: kotlin.String
): ResponseEntity<CreateCustomerResponse> {
        return ResponseEntity(HttpStatus.NOT_IMPLEMENTED)
    }


    @PostMapping(
            value = ["/customers"],
            produces = ["application/json"]
    )
    fun createCustomer( @RequestHeader(value="requestId", required=true) requestId: kotlin.String
): ResponseEntity<CreateCustomerResponse> {
        return ResponseEntity(HttpStatus.NOT_IMPLEMENTED)
    }

Steps to reproduce

Due to privacy constraints we can't paste more code here. However once we remove one of the two tags from the input, e.g.:

paths:
  /customers:
    post:
      tags:
        - customer
      summary: zzz
      operationId: createCustomer

then the generated Kotlin code does not contain a duplicate method createCustomer anymore.

Related issues/PRs

None

Suggest a fix

Do not generate a duplicate method even if multiple tags are provided for a given input.

Start by reproducing the issue with the YAML containing both customer and customer profile tags, then inspect the Kotlin generator involved in producing the duplicate createCustomer methods. No source files or tests are named in the report; done means the generated Kotlin contains only one method for the operation and compiles successfully.