[Bug Report] Qt: Unneccessary free space in tabs
### Description of Bug See attachments. There is unneccessary free space in every tab. OS: KDE neon 5.23 (based on Ubuntu 20.04) ![Screenshot_20211219_220456](/uploads/b1d84ec0b8710c1b3515aec1f1000084/Screenshot_20211219_220456.png) ![Screenshot_20211219_220522](/uploads/773cdc451c02f3b267f04de5284bd9ed/Screenshot_20211219_220522.png)
issue