libp2p: Circuit relay v2 server reservation refresh leaks abort listeners and allows remote resource exhaustion

libp2p is a JavaScript implementation of the libp2p networking stack. Prior to version 4.2.9, the reservation refresh path in reservation-store.ts reuses the same retimeableSignal but unconditionally registers another abort listener on every refresh. As a result, a remote peer can repeatedly send valid RESERVE requests for the same reservation, causing unbounded listener and closure growth in @libp2p/circuit-relay-v2 relay servers and leading to denial of service. This issue is fixed in version 4.2.9.