A brief summary of @Fp6’s workaround for the time being:
- App “Button Mapper” allows to deactivate the volume buttons
- To still have the option to change the volume, activate
System settings > Accessibility > Accessibility Menu > Accessibility Menu shortcut
This will put a green button on the right margin of your screen. Tapping on the green button allows you to change the volume (and other settings) without the physical button.