[BUG] Path problem of inout spec file in windows: Illegal character in opaque part at index 2: C:....\ApiFirstServer-main\build\openapiDir\petstore.yaml

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

Problem with path declaring of file with specification. Have an error: Illegal character in opaque part at index 2: C:....\ApiFirstServer-main\build\openapiDir\petstore.yaml

openapi-generator version

6.5.0

OpenAPI declaration file content or url

the issue doest link to file formatting

Generation Details

the issue doest link to file formatting

Steps to reproduce

• OS: windows
• gradle version: 7.5
• openapi-generator-plugin-version: "6.5.0"
• add plugin: id "org.openapi.generator" version "6.5.0"
• set inputspec in validation:

openApiValidate {
	inputSpec = "${buildDir}/openapiDir/petstore.yaml".toString()
}

or

openApiValidate {
	inputSpec = "${buildDir}\\openapiDir\\petstore.yaml".toString()
}

• get an error: Illegal character in opaque part at index 2: C:...\ApiFirstServer-main\build\openapiDir\petstore.yaml
• the same problem is in openApiGenerate phase

Related issues/PRs

Related issue: https://github.com/OpenAPITools/openapi-generator/issues/14075

Suggest a fix

just format link before loading the file.

Start with the Gradle plugin entry points used by openApiValidate and openApiGenerate, then reproduce the reported inputSpec paths on Windows with OpenAPI Generator 6.5.0. Trace how the Windows path is converted before the specification is loaded; done means both phases accept the forward-slash and backslash forms without the opaque-part error.