"File not found" error with Ranger when using Flatpak version

[olstach]

Describe the bug
When the Flatpak version of Foliate is set as the default app for epub files in Ranger, it displays a "Book cannot be opened: File not found" error. The snap version works fine.

To Reproduce
Steps to reproduce the behavior:

1. Add the following line to ~/.config/ranger/rifle.conf:
   ext epub, has com.github.johnfactotum.Foliate, X, flag f = com.github.johnfactotum.Foliate "$@"
2. Start Ranger in a new terminal session and try to open an .epub file

Expected behavior
Foliate opens the selected file correctly.

Version:

• Foliate version: 3.1.0
• OS/Distribution and version: Pop!_OS 22.04
• Desktop environment: GNOME 42.5
• Installation method: Flatpak

[johnfactotum]

Not familiar with Ranger, but to open files with Flatpak, you need to use --file-forwarding. See #1249.