Update gateway API dependency version to v0.5.0

[pmalek]

Whenever gateway API releases v0.5.0 we should strive to update our dependencies to account for that update.

Additionally, the hardcoded SHA of said dependency should reflect that update.

Related comment:

kubernetes-ingress-controller/Makefile

Lines 317 to 335 in be6366f

	# TODO: Below hardcoded ref is a workaround for the fact that we're using an untagged version
	# of sigs.k8s.io/gateway-api in go.mod - that occurred after v0.4.0 (which was tagged on master)
	# but which contains a breaking change w.r.t to the file structure in said repo - and the
	# fact that kustomize accepts only branch names, tags, or full commit hashes, i.e. short
	# hashes or go pseudo versions are not supported [1].
	# Please also note that kustomize fails silently when provided with an unsupported ref
	# and downloads the manifests from the main branch.
	#
	# [1]: https://github.com/kubernetes-sigs/kustomize/blob/master/examples/remoteBuild.md#remote-directories
	#
	# This causes a problem where we cannot use go pseudo version from go.mod i.e.
	# v0.4.1-0.20220306235253-71fee1c2808f and where we cannot update to a newer version
	# sigs.k8s.io/gateway-api because v0.5.0 hasn't been released yet and v0.4.x versions
	# do not contain the change in file structure that some of the code in this repo already
	# relies on.
	#
	# In order to avoid unnecessary work we're just hardcoding the full SHA that
	# corresponds to what's in go.mod - v0.4.1-0.20220306235253-71fee1c2808f - until
	# v0.5.0 is released which we can then use in go.mod and scrape via go list ...

This is orthogonal to supporting v1beta1 Gateway API in KIC which is covered by a combination of:

• Ensure that KIC is ready for upcoming Gateway API beta APIs #2570
• support for ReferencePolicy updates that have come in v0.5.0 Add controllers for ReferenceGrant #2690

Acceptance criteria

• KIC's go.mod requires gateway-api v0.5.0

[mflendrich]

GW API 0.5.0 is released.