fix: don't use check on generated _version

[tjohnson31415]

Description

setuptools_scm v10 no longer generates a _version file by default. We should be using importlib anyways though.

Related Issues

Test Plan

Manually verified both methods of obtaining the verion match:

from vllm_spyre._version import version as vllm_spyre_version
import importlib.metadata

vllm_spyre_version == importlib.metadata.version("vllm_spyre")

Also did a quick test with a manually generated precompiled model.

[joerunde]

lpgtm!

[github-actions]

👋 Hi! Thank you for contributing to vLLM support on Spyre.
Just a reminder: Make sure that your code passes all the linting checks, otherwise your PR won't be able to be merged. To do so, run ./format.sh.
Now you are good to go 🚀.

We also recommend installing prek and configuring it to check your code before every local commit.