Bump github.com/mattermost/mattermost-server/v6 from 6.1.0 to 6.3.0 (#1686)

Bumps [github.com/mattermost/mattermost-server/v6](https://github.com/mattermost/mattermost-server) from 6.1.0 to 6.3.0.
- [Release notes](https://github.com/mattermost/mattermost-server/releases)
- [Changelog](https://github.com/mattermost/mattermost-server/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mattermost/mattermost-server/compare/v6.1.0...v6.3.0)

---
updated-dependencies:
- dependency-name: github.com/mattermost/mattermost-server/v6
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

vendor/github.com/vmihailenco/msgpack/v5/msgpack.go

@@ -0,0 +1,52 @@
+package msgpack
+
+import "fmt"
+
+type Marshaler interface {
+	MarshalMsgpack() ([]byte, error)
+}
+
+type Unmarshaler interface {
+	UnmarshalMsgpack([]byte) error
+}
+
+type CustomEncoder interface {
+	EncodeMsgpack(*Encoder) error
+}
+
+type CustomDecoder interface {
+	DecodeMsgpack(*Decoder) error
+}
+
+//------------------------------------------------------------------------------
+
+type RawMessage []byte
+
+var (
+	_ CustomEncoder = (RawMessage)(nil)
+	_ CustomDecoder = (*RawMessage)(nil)
+)
+
+func (m RawMessage) EncodeMsgpack(enc *Encoder) error {
+	return enc.write(m)
+}
+
+func (m *RawMessage) DecodeMsgpack(dec *Decoder) error {
+	msg, err := dec.DecodeRaw()
+	if err != nil {
+		return err
+	}
+	*m = msg
+	return nil
+}
+
+//------------------------------------------------------------------------------
+
+type unexpectedCodeError struct {
+	code byte
+	hint string
+}
+
+func (err unexpectedCodeError) Error() string {
+	return fmt.Sprintf("msgpack: unexpected code=%x decoding %s", err.code, err.hint)
+}