fix: remove per-request queue listeners in abstract session

[Rinse12]

Closes #1101.

AbstractSession.retrieve() creates one Queue per block request and registers failure / success / idle listeners on it, but the finally only calls queue.clear(), which splices the job array and touches no listeners.

Queue extends TypedEventEmitter → native EventTarget. In a browser a listener-bearing EventTarget is kept alive by its own preserved wrapper, so every queue ever created stays a GC root along with the jobs, provider records and promise chains reachable from it. Excising them from a heap graph and re-running reachability showed the retained queues rooted 53.5% of the entire live heap; the count grew at ~930/h and reached 29,273 after 31.5 h in the app where this was found.

This keeps references to the three handlers and removes them in the same finally that already removes the provider and abort listeners.

Note for testing

This change does nothing on its own — main-event@1.0.4s removeEventListener never actually detaches (achingbrain/main-event#13, fix in achingbrain/main-event#14), so these new calls are no-ops until that lands. Issue #1101 has the detail. That is also why this went unnoticed: until main-event is fixed, every removeEventListener in the libp2p/helia tree is silently doing nothing.

Notes

• The three handlers were inline arrow functions; they are now named consts, which is the only reason the diff looks larger than three added lines.
• The event types come from QueueJobFailure / QueueJobSuccess, already exported from @libp2p/utils, and the queues job-options type is pulled into a local alias so the listener signatures can reuse it.
• I did not add emitEmpty.stop() / emitIdle.stop(): the debounce interval is 1 ms so a pending timer retains the queue only briefly, and it would mean reaching into @libp2p/utils internals. Happy to add it if you prefer.
• No test added — reproducing this needs GC-root reachability in a browser rather than anything observable from JS (listenerCount() cannot see it, and under the main-event bug it reports 0 regardless). Suggestions welcome if there is a shape you would accept.
• packages/utils does not currently typecheck from a clean npm install on main (unbuilt @helia/interface siblings); I verified this change introduces no new diagnostics in abstract-session.ts beyond the ones already present on main.