Fix: The withOptions method of OpenAIClientImpl cannot modify authentication credentials

[FanYaning]

Fix the issuses in #661 and #670

When modifying the API key or credentials via OpenAIClient by calling withOptions() on the client, the temporary client still uses the original client's authentication information.

OpenAIClient clientWithOptions = client.withOptions(opt -> {
        opt.apiKey("sk-test111111111111111111111111");
    });

    OpenAIClient clientWithOptions = client.withOptions(opt -> {
        opt.credential(BearerTokenCredential.create("sk-test111111111111111111111111"));
    });

[TomerAberbach]

Thanks! Can you run the formatter to fix CI?

[FanYaning]

Sorry for that! I have fix the format in #674