fix: disable terraform rollout wait and loosen readiness probe

[elliotechne]

• wait_for_rollout = false: Terraform apply no longer blocks on the rollout; the workflow's kubectl rollout status step handles monitoring
• readiness failure_threshold 2 -> 3: two consecutive failures (10s) was too aggressive during a rolling update with maxUnavailable=0, risking a stalled rollout hitting the progress deadline