cogl: Add main header for Cogl

This allows bindings linking to the C header to actually have the right one.

!1101
5 jobs for !1101 with tintou/cogl-gir-header in 9 minutes and 18 seconds (queued for 2 seconds)
detached
Status Job ID Name Coverage
  Review
passed #627395
check-commit-log

00:00:24

 
  Build
passed #627396
build-mutter

00:05:50

passed #627397
build-without-native-backend-and-wayland

00:01:22

 
  Test
passed #627399
can-build-gnome-shell

00:01:26

passed #627398
test-mutter

00:03:03