flatpak-spawn: Invalid byte sequence in conversion input

[silvasch]

Describe the bug
When opening a *.epub or a *.pdf file, foliate loads infinitely.

To Reproduce
Steps to reproduce the behavior:

1. Open foliate
2. Click on 'Open...'
3. Select your file
4. Spinner spins infinitely and doesn't load

Expected behavior
File should load

Screenshots

Version:

• Foliate version: 3.0.1
• OS/Distribution and version: Fedora 39
• Desktop environment: GNOME 45
• Installation method: Flatpak

Additional context
Logs:

(com.github.johnfactotum.Foliate:2): Gtk-WARNING **: 10:02:03.860: Locale not supported by C library.
	Using the fallback 'C' locale.
flatpak-spawn: Invalid byte sequence in conversion input
Try "flatpak-spawn --help" for more information.

(com.github.johnfactotum.Foliate:2): com.github.johnfactotum.Foliate-CRITICAL **: 10:02:13.672: My name is Oh-No-WebKit-Crashed, bug of bugs!

(com.github.johnfactotum.Foliate:2): com.github.johnfactotum.Foliate-CRITICAL **: 10:02:13.673: Look on this line, Developer -- despair!

[johnfactotum]

This is flatpak/flatpak#5564. See flatpak/flatpak#3712 (comment) and https://github.com/johnfactotum/foliate/blob/gtk4/docs/troubleshooting.md#-and-im-using-flatpak