bump vf (bc9fcd5)

[mikasenghaas]

bumps verifiers to include #832 which gives env server support for multiple env groups (used for training envs)

---

Note

Low Risk
Lockfile/dependency pin updates only; risk is limited to potential install or runtime regressions from the new verifiers/reverse-text versions.

Overview
Bumps verifiers to a newer git revision (3409cb5 �9 bc9fcd5) in pyproject.toml and uv.lock.

Cleans up dependency specification by removing the redundant reverse-text>=0.1.4 entry and updates the lockfile to reverse-text 0.1.5 (including dropping its previous datasets dependency).

^{Written by Cursor Bugbot for commit fa62c4b. This will update automatically on new commits. Configure here.}