Always reinstall eth2spec for non-editable installs

[danceratopz]

Adds --reinstall-package=eth2spec for uv run commands used with editable installs. This will ensure that uv doesn't used a cached version of eth2spec (consensus-specs) and ensure that the most recent version of repo source is used when generating test vectors during local development.

Follow-up fix to:

• Migrate config to pyproject.toml and use uv for project management #4627

and, in particular:

• Use non-editable installs for test generators #4634

[danceratopz]

Hi @jtraglia, does this resolve your comment from #4633?

Something here is causing me troubles too. I'm modifying gen_runner.py but the changes are not taking effect when re-executing. Pretty sure this has something to do with editable installs. Even deactivate and make clean don't make a difference.

[jtraglia]

Yes, I can confirm this fixes my issue. Thank you!