[calls] meson: Don't use deprecated Dependency.get_pkgconfig_variable()

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit 112098405bceefd8bc275f4d3cd1d924c28fe0bc
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Wed Dec 29 10:59:46 2021 +0100

    meson: Don't use deprecated Dependency.get_pkgconfig_variable()
    
    This function is deprecated since 0.56.0:
    
    WARNING: Project targeting '>= 0.56.0' but tried to use feature deprecated since
    '0.56.0': Dependency.get_pkgconfig_variable.
    use Dependency.get_variable(pkgconfig : ...) instead

 doc/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/doc/meson.build b/doc/meson.build
index afedc667..31c79ae1 100644
--- a/doc/meson.build
+++ b/doc/meson.build
@@ -2,7 +2,7 @@ if get_option('gtk_doc')
 
 subdir('xml')
 
-glib_prefix = dependency('glib-2.0').get_pkgconfig_variable('prefix')
+glib_prefix = dependency('glib-2.0').get_variable(pkgconfig : 'prefix')
 glib_docpath = join_paths(glib_prefix, 'share', 'gtk-doc', 'html')
 docpath = join_paths(get_option('datadir'), 'gtk-doc', 'html')