[BUG] [JAVA] NoSuchMethod org.yaml.snakeyaml.events.MappingStartEvent

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?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Build fails with Gradle 5.6.1

Expected: Build success
Actual: Failure:

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:service:openApiGenerate'.
> org.yaml.snakeyaml.events.MappingStartEvent.<init>(Ljava/lang/String;Ljava/lang/String;ZLorg/yaml/snakeyaml/error/Mark;Lorg/yaml/snakeyaml/error/Mark;Lorg/yaml/snakeyaml/DumperOptions$FlowStyle;)V

openapi-generator version

OpenApiGen 6.5.0

OpenAPI declaration file content or url

openapi: 3.0.0

info:
  title: example
  version: 1.0.0
  description: example
  contact:
    email: example@example.com

servers:
- url: http://example.com/v0

tags:
- name: example
  description: example
  externalDocs:
    description: example
    url: example

paths:
  '/example':
    get:
      tags: [example]
      summary: example
      operationId: example
      responses:
        '200':
          description: example
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Example'
        '404':
          description: example

components:
  schemas:
    Example:
      type: object
      description: example.
      required: [example]
      properties:
        example:
          type: integer
          description: example
          format: int32
          minimum: 0

Generation Details

openApiGenerate {
generatorName = "java"
generateApiDocumentation = false
generateApiTests = false
generateModelTests = false
generateModelDocumentation = false
inputSpec = "${project.projectDir}/src/main/webapp/WEB-INF/test.yaml".toString()
outputDir = "${project.projectDir}".toString()
packageName = "ch.test.ws"
apiPackage = "ch.test.ws.api"
invokerPackage = "ch.test.ws.client"
modelPackage = "ch.test.ws.model"
library = "resttemplate"
skipValidateSpec = true
configOptions = [
dateLibrary: "java8"
]
}

Steps to reproduce

Related issues/PRs

(https://github.com/OpenAPITools/openapi-generator/issues/2099)

Suggest a fix

Start by reproducing the failure from the Gradle openApiGenerate configuration shown in the issue, using OpenApiGen 6.5.0 and Gradle 5.6.1. Inspect the resolved SnakeYAML version and the MappingStartEvent constructor mismatch. Done means the provided Java generation setup completes successfully with the example OpenAPI declaration.