[BUG] [JAVA] InputSpecRootDirectory not working properly when we use path parameters - OpenAPI version 3.1.0

[chandu1a]

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 multiple Open API Yaml files which have paths containing path parameters.
When I generate the APIs individually from them using the inputSpec option it works as expected.
When I use the InputSpecRootDirectory option, the _merged_spec.yaml which is generated does not have the path parameters escaped properly.

The generated _merged_spec.yaml file contains paths like the below one which causes the validator to fail.

---
servers:
- url: "http://localhost:8080"
openapi: "3.1.0"
paths:
  /example-api/{param_a}:
    $ref: "./other-openapi.yaml#/paths/~1example-api~1{param_a}"

However what SHOULD be generated is the below as per
https://stackoverflow.com/questions/44150758/swagger-2-0-multiple-path-objects-with-different-paths-but-same-request-and-res/44164413#44164413

---
servers:
- url: "http://localhost:8080"
openapi: "3.1.0"
paths:
  /example-api/{param_a}:
    $ref: "./other-openapi.yaml#/paths/~1example-api~1%7Bparam_a%7D"

openapi-generator version

7.14.0

OpenAPI declaration file content or url

openapi: "3.1.0"
info:
  title: "Example API"
  description: "Example API"
  version: "1.0.0"
tags:
  - name: ExampleAPI
paths:
  /example-api/{param_a}:
    get:
      summary: "Example summary"
      operationId: "getExampleOperation"
      tags:
        - ExampleApi
      parameters:
        - name: "param_a"
          in: "path"
          required: true
          schema:
            type: "string"
      responses:
        "200":
          description: "OK"
          content:
            application/json:
              schema:
                $ref: "schemas/example-schemas.yaml#/components/schemas/ExampleResponse"

Generation Details

This was generated using the Maven Plugin version

Steps to reproduce

Generate using the Maven Plugin with the InputSpecRootDirectory option

Related issues/PRs

Suggest a fix

[chandu1a]

During further testing, I discovered that this issue is only present if we set the openapi version to 3.1.0.
The issue does not get recreated with version 3.0.0

i.e The below OpenAPI yaml works propertly

openapi: "3.0.0"
info:
  title: "Example API"
  description: "Example API"
  version: "1.0.0"
tags:
  - name: ExampleAPI
paths:
  /example-api/{param_a}:
    get:
      summary: "Example summary"
      operationId: "getExampleOperation"
      tags:
        - ExampleApi
      parameters:
        - name: "param_a"
          in: "path"
          required: true
          schema:
            type: "string"
      responses:
        "200":
          description: "OK"
          content:
            application/json:
              schema:
                $ref: "schemas/example-schemas.yaml#/components/schemas/ExampleResponse"