Flatpak: Add testing branch in the repository

Signed-off-by: Jerome Flesch <jflesch@openpaper.work>
4 jobs for testing in 46 minutes and 37 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #383219
volatile linux
check

00:04:17

canceled #383222
flatpak
linux_flatpak

00:01:46

passed #383221
msys2 windows
windows_exe

00:40:34

failed #383220
flatpak
linux_flatpak

00:00:03