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/google.golang.org/protobuf/protoadapt/convert.go

@@ -0,0 +1,31 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package protoadapt bridges the original and new proto APIs.
+package protoadapt
+
+import (
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/runtime/protoiface"
+	"google.golang.org/protobuf/runtime/protoimpl"
+)
+
+// MessageV1 is the original [github.com/golang/protobuf/proto.Message] type.
+type MessageV1 = protoiface.MessageV1
+
+// MessageV2 is the [google.golang.org/protobuf/proto.Message] type used by the
+// current [google.golang.org/protobuf] module, adding support for reflection.
+type MessageV2 = proto.Message
+
+// MessageV1Of converts a v2 message to a v1 message.
+// It returns nil if m is nil.
+func MessageV1Of(m MessageV2) MessageV1 {
+	return protoimpl.X.ProtoMessageV1Of(m)
+}
+
+// MessageV2Of converts a v1 message to a v2 message.
+// It returns nil if m is nil.
+func MessageV2Of(m MessageV1) MessageV2 {
+	return protoimpl.X.ProtoMessageV2Of(m)
+}