Make native sidecar default for proxy container (cleanup)

[aramase]

The PR to add native sidecar support for the proxy has been merged.

There is a check to determine whether the cluster is running the minimum required version. We should be able to remove this check once the webhook is only supported for clusters running version 1.32 or later.

azure-workload-identity/pkg/webhook/webhook.go

Lines 76 to 82 in ed30604

	// "SidecarContainers" went beta in 1.29. With the 3 version skew policy,
	// between API server and kubelet, 1.32 is the earliest version this can be
	// safely used.
	useNativeSidecar, err := serverVersionGTE(discoveryClient, utilversion.MajorMinor(1, 32))
	if err != nil {
	return nil, errors.Wrap(err, "failed to check kubernetes version")
	}