KEP-4004: promote stage to beta

[HirazawaUi]

• One-line PR description: Promote the stage of KEP to beta.

• Issue link: Deprecate status.nodeInfo.kubeProxyVersion field #4004

• Other comments:

[HirazawaUi]

/assign @danwinship

[sftim]

Note to KEP reviewers: I'd have named this gate LegacyNodeKubeProxyVersion or NodeKubeProxyVersion. I'ts feasible that we still can (by changing the feature gate name for beta)

Even when we intend to disable something, the feature gate is typically named after the thing we want to disable. It means in docs we don't ask people to, eg, “enable DisableNodeKubeProxyVersion” or “enable the DisableNodeKubeProxyVersion feature gate” - both of those jar, but the first one especially so.

[danwinship]

Do we ever do that? (Change a feature gate name between alpha and beta?)

If it matters, we're pretty sure no one will actually need to set this.

[sftim]

We have changed gate names, but I wouldn't think it's worth it here.

It was more feedback about how to review future KEPs.

[danwinship]

Do we ever do that? (Change a feature gate name between alpha and beta?)

If it matters, we're pretty sure no one will actually need to set this.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: danwinship, HirazawaUi
Once this PR has been reviewed and has the lgtm label, please ask for approval from wojtek-t. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• keps/prod-readiness/OWNERS
• keps/sig-network/OWNERS [danwinship]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment