fix: update to latest blender 4 version and use blender offical mirror

[lucasfcnunes]

This pull request updates the project to use Blender version 4.5.8 instead of 4.0.2 or earlier 4.5.x versions. The changes ensure that all references, installation steps, and documentation are consistent with the new Blender version.

Blender version update:

• Updated the Blender download URL and installation steps in the Dockerfile to use Blender 4.5.8 instead of 4.0.2, 4.3.2 or 4.5.5.
• Updated the commented example BLENDER_4 path in the Makefile to reference Blender 4.5.8.
• Updated the documentation in README.md to instruct users to set the BLENDER_4 environment variable to the Blender 4.5.8 binary path.