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/channels/app/telemetry.go

@@ -3,7 +3,7 @@
 
 package app
 
-import "github.com/mattermost/mattermost-server/v6/server/platform/services/telemetry"
+import "github.com/mattermost/mattermost-server/server/v8/platform/services/telemetry"
 
 func (s *Server) GetTelemetryService() *telemetry.TelemetryService {
 	return s.telemetryService