Update to go 1.21 and run `go mod tidy` #18

Annotations

10 errors

notebook.main calls manager.New, which eventually calls http2.ConfigureTransports

culler.UpdateNotebookLastActivityAnnotation calls fmt.Sprintf, which eventually calls http2.ConnectionError.Error

culler.UpdateNotebookLastActivityAnnotation calls fmt.Sprintf, which eventually calls http2.ErrCode.String

culler.UpdateNotebookLastActivityAnnotation calls fmt.Sprintf, which eventually calls http2.FrameHeader.String

culler.UpdateNotebookLastActivityAnnotation calls fmt.Sprintf, which eventually calls http2.FrameType.String

culler.UpdateNotebookLastActivityAnnotation calls fmt.Sprintf, which eventually calls http2.GoAwayError.Error

culler.UpdateNotebookLastActivityAnnotation calls fmt.Sprintf, which eventually calls http2.Setting.String

culler.UpdateNotebookLastActivityAnnotation calls fmt.Sprintf, which eventually calls http2.SettingID.String

culler.UpdateNotebookLastActivityAnnotation calls fmt.Sprintf, which eventually calls http2.StreamError.Error

culler.getNotebookResourceResponse calls http.Client.Get, which eventually calls http2.Transport.NewClientConn