Fail a stale uv lockfile before a Python deployment
A Python deployment can look reproducible right up to the moment its dependency declaration and lockfile disagree. pyproject.toml may request a different package version while uv.lock still describes the previous resolution. If CI creates an environment without checking that relationship first, the job can spend time building or downloading before it identifies the real problem. Worse, a workflow that updates the lockfile during deployment turns a reviewable source change into an environment-dependent side effect.