[BUG][Golang] Redeclaration error when a parameter has the name 'r'

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator?
• 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

I have a parameter with the name r. This causes a redeclaration error in the request builder since the name of the receiver is also r. A small example has been reproduced below.

openapi-generator version

7.14.0

OpenAPI declaration file content or url

Run openapi-generator-cli generate -i api.yaml -o output -g go and look at the output/api_default.go file.

openapi: 3.0.3
info:
  title: test
  version: 1.0.0
paths:
  /test:
    get:
      parameters:
        - name: r
          in: query
          style: form
          required: true
          schema:
            type: integer
      responses:
        200:
          description:
            Test description
          content:
            application/json:
              schema:
                type: integer

Suggest a fix

The receiver should not get the same name as the parameter. A single r as the parameter name could be renamed to something like r_ to avoid the conflict.

Run openapi-generator-cli generate -i api.yaml -o output -g go using the supplied OpenAPI declaration and inspect output/api_default.go. Confirm the parameter r conflicts with the request-builder receiver, then trace the Go generator template or source that names that receiver. Done means generated Go code compiles without a redeclaration error while preserving the parameter name.