[geary] meson: Remove uses of get_pkgconfig_variable

[Niels De Graef <nielsdg src gnome org>]

commit fa99f139005118b258bb4f46d9c3bab91c142f28
Author: Maximiliano Sandoval R <msandova gnome org>
Date:   Fri Jul 15 13:26:59 2022 +0200

    meson: Remove uses of get_pkgconfig_variable
    
    It will throw warnings on 0.56 or newer.

 meson.build                                  | 4 ++--
 src/client/plugin/messaging-menu/meson.build | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/meson.build b/meson.build
index a2cde71b0..ae8a84c79 100644
--- a/meson.build
+++ b/meson.build
@@ -119,7 +119,7 @@ icu_uc = declare_dependency(
 if libunwind_dep.found()
   # We need to add native lib to the search path for these so Flatpak
   # builds can find it.
-  unwind_lib = libunwind_dep.get_pkgconfig_variable('libdir')
+  unwind_lib = libunwind_dep.get_variable(pkgconfig: 'libdir')
   libunwind = declare_dependency(
      dependencies: [
        valac.find_library('libunwind', dirs: [vapi_dir, unwind_lib]),
@@ -207,7 +207,7 @@ vala_unit_dep = vala_unit_proj.get_variable('vala_unit_dep')
 
 # Language detection
 
-iso_codes_dir = iso_codes.get_pkgconfig_variable('prefix')/'share'/'xml'/'iso-codes'
+iso_codes_dir = iso_codes.get_variable(pkgconfig: 'prefix')/'share'/'xml'/'iso-codes'
 
 iso_639_xml = get_option('iso_639_xml')
 if iso_639_xml == ''
diff --git a/src/client/plugin/messaging-menu/meson.build b/src/client/plugin/messaging-menu/meson.build
index 7b3bb0abf..c89d2cbab 100644
--- a/src/client/plugin/messaging-menu/meson.build
+++ b/src/client/plugin/messaging-menu/meson.build
@@ -10,7 +10,7 @@ if libmessagingmenu_dep.found()
   # Vala libs manually
   messaging_menu_dependencies += declare_dependency(
     include_directories: include_directories(
-      libmessagingmenu_dep.get_pkgconfig_variable('includedir')
+      libmessagingmenu_dep.get_variable(pkgconfig: 'includedir')
     ),
     dependencies: [
       valac.find_library('MessagingMenu-1.0', dirs: [ '/usr/share/vala/vapi' ]),