fix: add missing dependencies to setup.cfg

[Helbronner]

• Added trimesh and pywavefront to install_requires in setup.cfg
• Sorted dependencies alphabetically to comply with project linting standards
• Resolved ModuleNotFoundError during runtime after an editable install

Closes #2459

Motivation

As discussed in #2459, trimesh and pywavefront are currently listed in requirements.txt but are missing from setup.cfg. This discrepancy leads to a silent failure in two critical scenarios:

1. Editable Install: Users who download the source code and run pip install -e . will have an incomplete environment. While the command finishes without errors, the library will crash at runtime with a ModuleNotFoundError.
2. Distribution Risk: If the package is uploaded to PyPI in its current state, a standard pip install manimgl will also result in a broken installation for the same reason, as PyPI distributions rely on the metadata defined in setup.cfg.

This Pull Request ensures that all necessary dependencies are centrally managed in setup.cfg, guaranteeing a consistent and robust setup experience for both developers and end-users.

Proposed changes

• Included trimesh and pywavefront in the install_requires list within setup.cfg
• Reorganized the dependency list alphabetically to maintain project consistency and simplify future maintenance.

Test

I verified the fix by performing a clean installation in an isolated virtual environment to ensure pip correctly resolves the new dependencies from setup.cfg.

Code:

# Create a clean virtual environment
python3 -m venv venv

# Enter the virtual environment (macOS)
source venv/bin/activate

# Install the project in editable mode (without -r requirements.txt)
python3 -m pip install -e .

# Run example_scenes.py
manimgl example_scenes.py OpeningManimExample -ol

Result:
The environment was initialized successfully without requiring manual dependency installation. The OpeningManimExample scene rendered correctly, confirming that the runtime errors are resolved.

Thanks for your time and review!