Revert "Introduces a forced WG handshake on initial MLKEM bootstrap."

This reverts commit b5a72eca65.

client/internal/engine.go

@@ -703,14 +703,6 @@ func (e *Engine) Start(netbirdConfig *mgmProto.NetbirdConfig, mgmtURL *url.URL)
 						conn.RequestReoffer()
 					}
 				},
-				// On a freshly bootstrapped PSK, force the peer's WireGuard session to
-				// re-handshake so it adopts the PSK even if the tunnel already came up on
-				// a pre-PQ key (KEM-vs-endpoint-config race).
-				rehandshake: func(remoteKey string) {
-					if conn, ok := e.peerStore.PeerConn(remoteKey); ok {
-						conn.ForcePQRehandshake()
-					}
-				},
 			}
 			e.pqkemManager = pqkem.NewManager(pqkem.LocalID(publicKey.String()), cbHandler, pqkem.NewLogger())
 			e.pqkemManager.Start(tr)