Gateway API: fix for failing GatewayWithAttachedRoutes conformance test

[skriss]

As of Gateway API v1.0.0-rc2, the GatewayWithAttachedRoutes conformance test has started failing. This is related to how attached routes are counted when a Gateway is invalid. ref. kubernetes-sigs/gateway-api#2477

[izturn]

i'd like to work on it

[sunjayBhatia]

looks like there is some work upstream going on for this test: kubernetes-sigs/gateway-api#2548

[sunjayBhatia]

Recent history on this test follows these PRs:

• Conformance: Adds Test to Exercise Gateway AttachedRoutes kubernetes-sigs/gateway-api#2477
• Fix bugs in GatewayWithAttachedRoutes kubernetes-sigs/gateway-api#2535
• Fix attached routes confromance test kubernetes-sigs/gateway-api#2548