v8.0 module release (#22975)

https://mattermost.atlassian.net/browse/MM-52079

```release-note
We upgrade the module version to 8.0. The new module path is github.com/mattermost-server/server/v8.
```


Co-authored-by: Doug Lauder <wiggin77@warpmail.net>

server/model/cluster_info.go

@@ -0,0 +1,12 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+type ClusterInfo struct {
+	Id         string `json:"id"`
+	Version    string `json:"version"`
+	ConfigHash string `json:"config_hash"`
+	IPAddress  string `json:"ipaddress"`
+	Hostname   string `json:"hostname"`
+}