Linux - Embed AppImage update information

### Feature area

Desktop app

### Description

AppImage Delta updates

When trying to update via [AppImageUpdate](https://github.com/AppImageCommunity/AppImageUpdate)

This is a common standard for updating AppImages.
AppImage having update information would also recognized by other software e.g. [AppImageLauncher](https://github.com/TheAssassin/AppImageLauncher), [AppManager](https://github.com/kem-a/AppManager), [AM](https://github.com/ivan-hc/AM) etc...

info:
- https://github.com/AppImageCommunity/AppImageUpdate#update-information-overview
- https://github.com/AppImage/AppImageSpec/blob/master/draft.md#update-information
- https://github.com/ivan-hc/AppImage-tips#how-to-add-delta-updates

Lots of projects already support updating AppImage e.g: [LibreWolf](https://gitlab.com/librewolf-community/browser/appimage/-/releases), [KeePassXC](https://github.com/keepassxreboot/keepassxc/releases), [Sigil](https://github.com/Sigil-Ebook/Sigil/releases) etc.

### Problem it solves

Updating will take less amount of data and time due to downloading only `diff`.

### Alternatives considered

_No response_

### Additional context

_No response_

No repository file or test is named. Start by locating the Linux desktop AppImage packaging entry point and compare its artifact metadata with the AppImageUpdate specification linked in the issue. Done means the produced AppImage embeds standard update information recognized by AppImageUpdate and other listed tools.

Written by the indexing model from the issue text.