meson: Fix invalid keyword warning

"required" keyword is not a valid argument for has_header()

WARNING: Passed invalid keyword argument "required".
WARNING: This will become a hard error in the future.
2 jobs for fix-meson-warning in 2 minutes and 55 seconds (queued for 3 minutes and 36 seconds)
Status Job ID Name Coverage
  Manifest
passed manifest #43265

00:01:22

 
  Build
passed build fedora x86_64 #43266

00:01:33