Appimage Release improvement for Gearlever updating

## Feature request

**Which Nextcloud Version are you currently using:**
33.07

**Is your feature request related to a problem? Please describe.**
I am using Gearlever to manage my Appimages on Ubuntu26.04 and would like to automate the updating process, which requires either a static URL, so one that always points towards the latest release, or a github release including the Appimage file with a static naming pattern.
**Describe the solution you'd like**
I would like it if the official website could use a static URL to point to the latest Appimage instead of one that points to the latest but always changes with each realease.
**Describe alternatives you've considered**
Alternatively a Github release, which includes the Appimage file would also work for me
**Additional context**
Great job so far and keep up the good work <3

Start by inspecting the official website's current AppImage download link and the GitHub release process for the desktop client. Compare how the latest artifact is named and published, then confirm that a stable download target or predictable release asset can be updated automatically and tested from Gearlever.

Written by the indexing model from the issue text.