Contour 1.24 should pick up Gateway API v0.6.0.

Sub-tasks:

• Gateway API: ReferencePolicy -> ReferenceGrant rename #4555
• Gateway Scheduled -> Accepted condition (add GatewayConditionAccepted and GatewayReasonAccepted kubernetes-sigs/gateway-api#1447)
• Listener Detached: true -> Accepted: false (Detached) (add ListenerConditionAccepted, update docs from "Detached" kubernetes-sigs/gateway-api#1446)