DesktopIntegration class is inner in LinuxPackageBundler.
Just because it depends on LinuxPackageBundler.fetchResource(). It would be good to have these classes separated.

fetchResource() is declared in AbstractBundler class. Similar functionality is provided by AbstractAppImageBuilder.locateResource().

AbstractAppImageBuilder.preprocessTextResource() is a copy/paste of AbstractBundler.preprocessTextResource() or vice versa that both provide similar functionality to fetchResource() plus text substitution.

Move preprocessTextResource() and fetchResource() to a separate class that can be used by bundler classes and by DesktopIntegration class. This would eliminate code duplication between AbstractBundler and AbstractAppImageBuilder classes and allow to decouple DesktopIntegration and LinuxPackageBundler classes.