blendify 2.1.0 Release

This release brings the support of the latest Blender 4.5 LTS version to blendify.

Summary of changes

• Updated the code to rely on Blender 4.5.2 LTS and Python 3.11;
• Switched build logic to use pyproject.toml instead of setup.py;
• Feature: updated rendering with shadow catchers to have transparent background;
• Internal: updated material cleaning to unlink materials from objects to ensure proper cleanup;
• Internal: added force exit logic using atexit to circumvent Blender's bug with hanging process during memory cleanup on exit;

Breaking changes

several changes were required to match the updated Blender API:

• Lights: renamed cast_shadows to use_shadow;
• Materials: renamed material properties to match the updated Blender API (Clear Coat -> Coat IOR, Specular -> Specualr IOR Level, etc.).