Add support for GPT-5.4 in API Nodes

### Feature Idea

### Description
Current API nodes in the repository only support **GPT-5**. I would like to request the addition of support for the **GPT-5.4** model to take advantage of its improved reasoning capabilities and updated API parameters.

### Motivation
- **Enhanced Performance:** GPT-5.4 offers significantly better multi-modal understanding which is crucial for complex ComfyUI workflows.
- **Workflow Continuity:** As my production environment shifts towards the 5.4 model, having native node support will prevent the need for custom Python script workarounds.

### Proposed Solution
- Update the model selection dropdown in the `GPT API Node` to include `gpt-5.4`.
- Update the underlying API call logic to handle the specific requirements of the 5.4 endpoint (if any).

### Existing Solutions

_No response_

### Other

_No response_