Bookmarks Export Menu Missing Spacing Between Icon and Text

### Describe the bug

The expected spacing between the icon and text is missing, causing them to overlap. See attached screenshot.


### Expected behavior

_No response_

### Screenshots

_No response_

### OS

Mac OS

### OS - Others

_No response_

### Firefox Version

v136

### Distribution

- [x] [Original Lepton](https://github.com/black7375/Firefox-UI-Fix)
- [ ] [Lepton's photon style](https://github.com/black7375/Firefox-UI-Fix/tree/photon-style)
- [ ] [Lepton's proton style](https://github.com/black7375/Firefox-UI-Fix/tree/proton-style)

### Theme

- [ ] Light
- [ ] Dark
- [ ] Alpenglow (System: Light)
- [ ] Alpenglow (System: Dark)
- [x] System Default
- [ ] Others: (e.g. [Photon Colors](https://addons.mozilla.org/en-US/firefox/addon/photon-colors/), [Google Chrome Dark](https://addons.mozilla.org/en-US/firefox/addon/google-chrome-dark/), [Fairytale Of Nature](https://addons.mozilla.org/en-US/firefox/addon/fairytale-of-nature/))

### Theme - More Info

_No response_

### `user.js` setup

user.js setup

```javascript
// Default
```

### Additional context

This issue has been present for a long time.

Reproduce the bookmarks export menu in Firefox 136 on macOS with the Original Lepton distribution and System Default theme. Search the SCSS styles for the bookmarks export menu and compare the icon and text spacing against the attached screenshot. Done means the icon and label no longer overlap while the menu remains usable.

Written by the indexing model from the issue text.