Relax PyOpenGL version requirement to support OSMesa for offscreen rendering

[javierganan99]

Solves #293. This PR relaxes the PyOpenGL version dependency, enabling compatibility with OSMesa for offscreen rendering. Testing was conducted on Python versions 3.10 through 3.12, across both Ubuntu (22.04 and 24.04) and Fedora, using PyOpenGL 3.1.7.

Steps to enable OSMesa-based offscreen rendering:

Install OSMesa ang GLU libraries:

Debian-based distributions (e.g., Ubuntu, Debian):

apt-get install libosmesa6-dev libglu1-mesa

Red Hat-based distributions (e.g., Fedora, RHEL, CentOS, AlmaLinux, Rocky Linux):

dnf -y install mesa-libGL mesa-libOSMesa-devel mesa-libGLU

Once the appropriate packages are installed, set the environment variable PYOPENGL_PLATFORM=osmesa either in your shell or within your Python script:

import os
os.environ["PYOPENGL_PLATFORM"] = "osmesa"
import pyrender
# Your rendering code here