Bug#706798: retry spek and yorick-av with libav 9.10?

["Rebecca N. Palmer" <r.palmer@bham.ac.uk>]

The spek test crash (#725385, s390x) happens inside libav, and the 
yorick-av test crash (#722610, armhf) occurs on dereferencing a pointer 
that should come from libav; it is hence possible that these are fixed 
by the new (9.10) libav.  Can someone try that?