misprite: Stop wrapping GetImage/GetSpans

SourceValidate handles this for us consistently now.

Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>
3 jobs for getimage-validate in 5 minutes and 59 seconds (queued for 16 seconds)
Status Job ID Name Coverage
  Docker Image
passed #846155
debian-testing

00:00:20

 
  Build And Test
passed #846157
autotools-build-and-test

00:05:38

passed #846159
meson-build-and-test

00:02:33