flatpak: add opencv_contrib

This adds opencv_contrib modules while building pitivi.
4 jobs for master in 81 minutes and 15 seconds (queued for 3 seconds)
Status Name Job ID Coverage
  Docker Image
passed pitivi:1.0 #788904
privileged

01:09:56

passed pitivi:master #788903
privileged

01:11:23

 
  Build
passed build #788906
flatpak

00:09:37

 
  Deploy
passed deploy #788908
PitiviBuildMachine

00:00:14