ci(dev): make the release gates wait for the runner they grade

The acceptance suites steer real fleets, so they measure the bare-metal
runner's behaviour and not just the API's — but `worker` is a parallel
branch of the graph that nothing waited on. Ordering was left to luck: on
the run that surfaced this, the worker deploy finished ten seconds before
the suites started. A slower deploy and the suites grade the PREVIOUS
runner, reporting a fixed fault as still broken, or a broken one as fixed.

Plain `needs` gives the right semantics with no `if:` gymnastics. A
documented DEV_WORKER_READY=false skip still lets the gates run: the
called workflow's `result` job is `if: always()`, so a skipped deploy
concludes success. A FAILED worker deploy skips the gates, which the
verdict already reads as red — the honest reading, since nothing was
measured. `verify waits only on Fly` is untouched.

Found while asking whether this branch's invalid-model negative would
actually pass in CI: it asserts the runner surfaces a provider's cause
line, which only holds once the new runner is live.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>