feat(gateway): update to Gateway API v0.5.0, support v1beta1 resources

[michaelbeaumont]

Summary

This removes the upstream validator from our webhooks since it's installed as part of the upstream resource bundle. Until we no longer rely on users installing the upstream bundle, I don't think it makes sense to run the webhook ourselves.

Some conformance tests changed and are disabled here until #4597

[codecov-commenter]

Codecov Report

Merging #4599 (3dda7bf) into master (ea66f01) will decrease coverage by 0.01%.
The diff coverage is 54.28%.

@@            Coverage Diff             @@
##           master    #4599      +/-   ##
==========================================
- Coverage   46.76%   46.74%   -0.02%     
==========================================
  Files         678      678              
  Lines       45645    45653       +8     
==========================================
- Hits        21344    21340       -4     
- Misses      22432    22442      +10     
- Partials     1869     1871       +2     

Impacted Files	Coverage Δ
...8s/controllers/gatewayapi/attachment/attachment.go	69.41% <ø> (ø)
...untime/k8s/controllers/gatewayapi/common/common.go	0.00% <ø> (ø)
...controllers/gatewayapi/gateway_class_controller.go	0.00% <ø> (ø)
...e/k8s/controllers/gatewayapi/gateway_controller.go	0.00% <ø> (ø)
...e/k8s/controllers/gatewayapi/gateway_conversion.go	33.17% <ø> (ø)
...ntime/k8s/controllers/gatewayapi/gateway_status.go	0.00% <ø> (ø)
...8s/controllers/gatewayapi/http_route_controller.go	0.00% <ø> (ø)
...8s/controllers/gatewayapi/http_route_conversion.go	0.00% <ø> (ø)
...me/k8s/controllers/gatewayapi/http_route_status.go	0.00% <ø> (ø)
...ime/k8s/webhooks/gatewayapi_multizone_validator.go	40.90% <50.00%> (+3.40%)	⬆️
... and 4 more

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[lahabana]

@michaelbeaumont what's the upgrade story here? Is everything just working out of the box and gateway api has all the upgrade webhooks?

[michaelbeaumont]

It just relies on k8s mechanisms to handle different versions. Resources are always stored as v1alpha2 (this is defined in the upstream CRDs and means there's no storage migration necessary) but can be accessed using either v1alpha2 or v1beta1 APIs. Since they are identical I believe no webhooks are necessary.