feat: add multimodal extras and remove pydub for Python 3.13 compatibility

[rdheekonda]

Reorganizes optional dependencies into a multimodal extras group and removes pydub dependency to ensure Python 3.13 compatibility.

📋 Changes

Dependencies

• Group multimodal dependencies: soundfile, moviepy
• Remove pydub dependency (Python 3.13 compatibility issue)
• Add multimodal extras: pip install dreadnode[multimodal]
• Keep training extras separate: pip install dreadnode[training]

Code Changes

• Update Audio class to remove pydub AudioSegment support
• Add graceful import guards with helpful error messages
• Add VideoClip detection when moviepy not installed
• Version bump to v1.0.9

Documentation

• Add installation instructions for multimodal extras

🔧 Installation

Users can now install with:

# Core package
pip install dreadnode

# With multimodal support  
pip install dreadnode[multimodal]

# Training only
pip install dreadnode[training]

# Everything
pip install dreadnode[multimodal,training]
---

## Generated Summary:

- Updated `README.md` to include installation instructions for optional multimodal extras, enhancing users' ability to install additional media processing capabilities.
- Removed support for `pydub.AudioSegment` in both the `Audio` data type and the related example notebook, simplifying the audio handling functionality.
- Added ImportError checks in the codebase to ensure that required dependencies like `soundfile` and `moviepy` are available when using specific audio or video functionalities, improving error handling and user experience.
- Updated the version in `pyproject.toml` from `1.0.8` to `1.0.9`, reflecting these changes and ensuring version consistency across the project.
- Adjusted example Jupyter notebooks to remove references to `pydub.AudioSegment` and included notes for users to install multimodal extras for full functionality.

This summary was generated with ❤️ by [rigging](https://rigging.dreadnode.io/)