hack/tools: remove openapi-gen install in vendor

Signed-off-by: Damien Grisonnet <dgrisonn@redhat.com>

hack/tools.go

@@ -0,0 +1,23 @@
+// Copyright 2021 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.
+
+// +build tools
+
+// Package tools tracks dependencies for tools that used in the build process.
+// See https://github.com/golang/go/wiki/Modules
+package tools
+
+import (
+	_ "k8s.io/kube-openapi/cmd/openapi-gen"
+)