Add libappimageupdate to the releases

[Korne127]

Currently, both the dynamic and the static version of libappimageupdate are not uploaded to Github releases. This means that every developer who wants to use that has to build the project themselves, which is additional tedious work. Especially since the build instructions are outdated and incomplete, it would be good to adapt the Github Actions script to also upload these (and possibly other missed) libraries.