docs: update OpenAI page Vision section

[NanKisu]

📄 Documentation Bug

Problem:
#3486
In the 1.0.0 version of the documentation, the Vision example shown is actually from version 1.1.0-SNAPSHOT. Shouldn't the example below be included instead if it's truly the 1.0.0 documentation?

Suggested Fix:
Update OpenAI page Vision section

Version: Spring AI 1.0.0

[sobychacko]

I don't think it really matters which version of the test that we are linking here as the users will not really see what version we are linking to. More than that, since 1.0.0 is already out, the next version will be 1.0.1 and ideally we should point to the latest snapshot from 1.0.x. But, it doesn't really matter what we are linking to since we are showing some code examples mainly from a test.

[NanKisu]

Thank you for the review!

I think the example code currently shown in the documentation is not correct for version 1.0.0.
Specifically, this part:

var userMessage = new UserMessage("Explain what do you see on this picture?",
        new Media(MimeTypeUtils.IMAGE_PNG, this.imageResource));

ChatResponse response = chatModel.call(new Prompt(this.userMessage,
        OpenAiChatOptions.builder().model(OpenAiApi.ChatModel.GPT_4_O.getValue()).build()));

I’m planning to replace it with the following, which I believe reflects the correct usage:

var userMessage = UserMessage.builder()
    .text("Explain what do you see on this picture?")
    .media(List.of(new Media(MimeTypeUtils.IMAGE_PNG, imageData)))
    .build();
var response = this.chatModel
    .call(new Prompt(List.of(userMessage), OpenAiChatOptions.builder().model(modelName).build()));

For the same reason, I updated the test code link to point to the version where this correct example is actually used. The previous link was referencing code that I thought was incorrect.