meson: add include directory to the generated pkg-config file

Fixes 300ddc70
7 jobs for abderrahim/pkg-config-include in 15 minutes and 8 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #466192
fedora:asan

00:09:44

passed #466194
fedora:coverage

00:09:10

69.9%
passed #466445
fedora:ubsan

00:04:43

passed #466191
fedora:Werror

00:09:55

failed #466193
fedora:ubsan

00:03:04

 
  Deploy
passed #466195
pages

00:00:29

passed pages:deploy

00:00:00