Pull a docker image of an old distro into an apptainer sandbox, install what you need within, then make a .sif image, should work pretty much in perpetuity. You can also try to make an Appimage.
Abrechnung is really good and actively developed and improving. The UI is already pretty satisfactory, and there’s also an API which is needed if for example you want to bulk-import a spreadsheet, for now you have to code it a bit.