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/wsapi/websocket_handler.go

@@ -6,11 +6,11 @@ package wsapi
 import (
 	"net/http"
 
-	"github.com/mattermost/mattermost-server/v6/model"
-	"github.com/mattermost/mattermost-server/v6/server/channels/app"
-	"github.com/mattermost/mattermost-server/v6/server/channels/app/platform"
-	"github.com/mattermost/mattermost-server/v6/server/platform/shared/i18n"
-	"github.com/mattermost/mattermost-server/v6/server/platform/shared/mlog"
+	"github.com/mattermost/mattermost-server/server/v8/channels/app"
+	"github.com/mattermost/mattermost-server/server/v8/channels/app/platform"
+	"github.com/mattermost/mattermost-server/server/v8/model"
+	"github.com/mattermost/mattermost-server/server/v8/platform/shared/i18n"
+	"github.com/mattermost/mattermost-server/server/v8/platform/shared/mlog"
 )
 
 func (api *API) APIWebSocketHandler(wh func(*model.WebSocketRequest) (map[string]any, *model.AppError)) webSocketHandler {