Add Rich-based SVG Rendering for program-output

[mgaitan]

This PR introduces the ability to render program output using Rich in an SVG format. When Rich mode is active, the output is styled with colors and formatting, resulting in a nicer visual appearance compared to a standard literal block.

How It Works

• Global Enable: Set programoutput_force_rich = True in your conf.py to force Rich for all directives.
• Per Directive: Use the :rich: option on a .. program-output:: directive.
• Width and Colors: Rich respects environment variables like COLUMNS (to set the console width) and FORCE_COLOR (to force ANSI colors).

Example Usage

.. command-output:: python -m rich
   :rich:

PS: in addition I upgraded pyproject.toml and removed setup.py