Dialogs can have 2 overlapping scrollbars with one inaccessible on lower browser widths

### Steps to reproduce

1. Open a room or user settings dialog
2. Set the browser width to 1/3rd of your screen. (spotted on 1920x1200 screen by using the windows function of dragging the browser-window to the top and choosing the 1/3rd of screen-width option)
3. Attempt to scroll horizontally to reveal dialog content you can't see

### Outcome

#### What did you expect?
- Either one scrollbar or 2 that are both accessible.

#### What happened instead?
- A first scrollbar on the full dialog which cannot be used to reveal settingstab content that is out of view.
- A second scrollbar underneath it for the settingstab content which cannot be reached with the mouse.
- Thus the settingstab content that is out of view can only be revealed through a click inside of the component and using arrow keys or selecting text to drag it into view.

### Operating system

_No response_

### Browser information

_No response_

### URL for webapp

_No response_

### Application version

_No response_

### Homeserver

_No response_

### Will you send logs?

No