meson: check that headers are self-contained

Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
4 jobs for headers-self-contained in 2 minutes and 4 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Containers
passed #926445
arch

00:00:19

passed #926444
debian

00:00:21

 
  Build
passed #926447
meson-arch

00:01:25

passed #926446
meson-debian

00:01:43