Ingress holding-buffer recovery requires releasing egress first

In a closed-loop switch+scheduler, tx5_ingress_ready (data_in_ready) only returns high when a packet retires from the ingress holding buffer, which requires a grant. Grants require destination occupancy below GRANT_LIMIT. So a backpressure test that never releases the egress read-enable just times out and never observes recovery. Drive egress read high, then wait for ready to rise and for the stalled packet to appear at the egress port.