[Java][Feign]Remove oauth related code for non secured apis

[hugo-ma-alves]

Hello

On the previous PR https://github.com/OpenAPITools/openapi-generator/pull/8318/files I forgot to take in account the cases where the API does not have any authentication mechanism.
If we use the current version of openapi-cli to generate the client for a non secured api, we will get Oauth related code on the output but not the required dependencies on the pom.xml/gradle.

This PR removes the unnecessary code when the api is not configured to use authentication.

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[TobsCore]

The previous version breaks our build, since scribejava was not present as a library. After adding it, the generated classes will cause compile errors, since the OAuth class was not present and neither was OAuthFlow (enum?).

Therefore this change is very welcome. We are currently stuck on v5.0.0.

[pPanda-beta]

Good one, we really need this!

@hugo-ma-alves do you know any workarounds until this PR gets released?

[hugo-ma-alves]

Hello @pPanda-beta

A quick and dirty workaround is to delete the affected code.

On ApiClient.java

private RequestInterceptor buildOauthRequestInterceptor(OAuthFlow flow, String authorizationUrl, String tokenUrl, String scopes) {
    switch (flow) {
      case password:
        return new OauthPasswordGrant(tokenUrl, scopes);
      case application:
        return new OauthClientCredentialsGrant(authorizationUrl, tokenUrl, scopes);
      default:
        throw new RuntimeException("Oauth flow \"" + flow + "\" is not implemented");
    }
  }

And delete the following files:

• OauthPasswordGrant
• OauthClientCredentialsGrant

[wing328]

@hugo-ma-alves thanks for the PR but sorry that I missed it. I've done it via #9760 instead (merged into master). Can you please pull the latest master to give it a try?

Happy to reopen this one if needed.

[hugo-ma-alves]

Thanks @wing328
Looks good!