eval-py allow outputting images

[G4Vi]

No description provided.

[G4Vi]

Started in https://github.com/dylibso/mcp.run-servlets/tree/gavin/20250127-improve-eval-py, putting on hold for now:

Outputting images is useless without being able to generate valid images. The standard way to Python to generate images appears to be the Pillow library. The Pillow library cannot easily be added to eval-py as it depends on native code. I experimented with trying to have Claude generate image generating code (without third-party libraries) and was largely unsuccessful, either the outputted image was not valid or it did not match the prompt.

This can be picked back up when the python-pdk supports adding native libraries and/or AI models are better at generating image files from scratch.