fix: re-resolve uv.lock to downgrade Pygments to 2.19.2 (#187)

## Summary

- Re-resolves `uv.lock` to actually downgrade Pygments from 2.20.0 to
2.19.2
- The previous fix (#185) added `Pygments<2.20` to `pyproject.toml` but
never re-resolved the lockfile (`uv lock` used a cached resolution), so
CI continued installing 2.20.0
- This is why the docs build is still failing on main — `uv sync --group
docs` installs from the lockfile, which still had 2.20.0

## Test plan

- [ ] CI docs build passes (the `Build Documentation` job that's been
failing)

Author: smoreinis