update-vanity-imports.sh: remove script

With the "// import ..." statements removed form all files, we no
longer need the update script which would add them back.

hack/update-vanity-imports.sh

@@ -1,32 +0,0 @@
-#!/usr/bin/env bash
-
-# Copyright 2024 The Kubernetes Authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# This script fixes the vanity imports programmatically.
-# Usage: `hack/update-vanity-imports.sh`.
-
-set -o errexit
-set -o nounset
-set -o pipefail
-
-KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
-source "${KUBE_ROOT}/hack/lib/init.sh"
-
-kube::golang::verify_go_version
-
-go -C "${KUBE_ROOT}/hack/tools" install github.com/jcchavezs/porto/cmd/porto
-
-porto --restrict-to-dirs="staging" --restrict-to-files="doc\\.go$" -w "${KUBE_ROOT}"
-