Update versioning to use importlib

[ahmrr]

Motivation

Using pkg_resources is deprecated and slated for removal:

Use of pkg_resources is deprecated in favor of importlib.resources, importlib.metadata and their backports (importlib_resources, importlib_metadata).

Thus, running manim on e.g. Python 3.11.13 results in the following warning:

UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The > pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.

Proposed changes

I simply updated the versioning code in __init__.py to use importlib.metadata instead of pkg_resources.

Test

Code:

$ manim --version

Result:

ManimGL v1.7.2

[azhuchkov]

Unfortunately, this PR (apparently useful) duplicates another one: #2360.

[ahmrr]

You're right, my apologies; I should have checked the other pull requests.