Publish AppImage as a standalone release asset

Linux `.appimage` releases are currently being zipped.

AppImages are already self-contained and are intended to be distributed as standalone files. Wrapping the AppImage in another archive breaks some tools and utility helpers (like `appimaged` or [Gear Lever](https://github.com/mijorus/gearlever)) and is also discouraged in the [AppImage Documentation](https://docs.appimage.org/packaging-guide/distribution.html#do-not-put-appimages-into-other-archives).

Would it be possible to publish the AppImage without zipping it, or provide both zipped and standalone variants?

Read the linked AppImage Documentation guidance, then locate the Linux release packaging configuration that creates the zipped .appimage asset. Verify the release publishes a standalone AppImage that works with appimaged or Gear Lever, and confirm the resulting release assets match the requested standalone or dual-variant distribution.

Written by the indexing model from the issue text.