build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/k8s.io/client-go/tools/remotecommand/fallback.go

@@ -0,0 +1,60 @@
+/*
+Copyright 2023 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.
+*/
+
+package remotecommand
+
+import (
+	"context"
+
+	"k8s.io/klog/v2"
+)
+
+var _ Executor = &FallbackExecutor{}
+
+type FallbackExecutor struct {
+	primary        Executor
+	secondary      Executor
+	shouldFallback func(error) bool
+}
+
+// NewFallbackExecutor creates an Executor that first attempts to use the
+// WebSocketExecutor, falling back to the legacy SPDYExecutor if the initial
+// websocket "StreamWithContext" call fails.
+// func NewFallbackExecutor(config *restclient.Config, method string, url *url.URL) (Executor, error) {
+func NewFallbackExecutor(primary, secondary Executor, shouldFallback func(error) bool) (Executor, error) {
+	return &FallbackExecutor{
+		primary:        primary,
+		secondary:      secondary,
+		shouldFallback: shouldFallback,
+	}, nil
+}
+
+// Stream is deprecated. Please use "StreamWithContext".
+func (f *FallbackExecutor) Stream(options StreamOptions) error {
+	return f.StreamWithContext(context.Background(), options)
+}
+
+// StreamWithContext initially attempts to call "StreamWithContext" using the
+// primary executor, falling back to calling the secondary executor if the
+// initial primary call to upgrade to a websocket connection fails.
+func (f *FallbackExecutor) StreamWithContext(ctx context.Context, options StreamOptions) error {
+	err := f.primary.StreamWithContext(ctx, options)
+	if f.shouldFallback(err) {
+		klog.V(4).Infof("RemoteCommand fallback: %v", err)
+		return f.secondary.StreamWithContext(ctx, options)
+	}
+	return err
+}