Retire the bloom-storm chaos scenario from both CI runners

The scenario guarded a real regression: a mid-chain tree update that
changed neither root nor depth leaking downstream as a sustained bloom
announce storm. But it was never once run against the regressed binary,
and its per-node ceiling was inferred from a post-mortem harness that no
longer exists in the tree. On the only surviving regressed measurement
the tail node's rate scales to roughly 7 sends per 30s, well under the
scenario's ceiling of 40, so it was never established that the assertion
could fire on its own bug class. The ceiling is also uniform per node,
calibrated against the flap target that is legitimately busy rather than
against the tail where the storm actually shows.

This removes coverage rather than relocating it, unlike the two earlier
retirements above it, and the comment in ci-local.sh records that gap
explicitly. The scenario, its README, the link_swap sim primitive and the
mesh-lab dispatch all stay on disk, so it remains runnable by hand.

Parity holds at 24 legs a side. The parity guard was break-checked by
re-adding the GitHub leg alone, which correctly reported the asymmetry.

.github/workflows/ci.yml

@@ -408,9 +408,6 @@ jobs:
           - suite: congestion-stress
             type: chaos
             scenario: congestion-stress
-          - suite: bloom-storm
-            type: chaos
-            scenario: bloom-storm
           # ── Sidecar deployment ──────────────────────────────────────────
           - suite: sidecar
             type: sidecar