ADDED MLX FOR SUPER FAST GENERATIONS ON APPLE SILICON

- Added support for MLX backend on Apple Silicon, enabling optimized performance for TTS and STT tasks.
- Updated release workflow to include MLX-specific dependencies and configurations for macOS platforms.
- Refactored backend code to dynamically select between MLX and PyTorch based on the runtime environment.
- Enhanced model loading and inference logic to accommodate backend-specific requirements, including updated model IDs and hidden imports.
- Improved health check and model status reporting to reflect the active backend type.
- Streamlined caching mechanisms to support both backend types, ensuring compatibility and performance.

backend/requirements-mlx.txt

@@ -0,0 +1,5 @@
+# MLX-specific dependencies (Apple Silicon only)
+# These should only be installed on aarch64-apple-darwin platforms
+
+mlx>=0.30.0
+mlx-audio>=0.3.1