[gtksourceview] build: only define DATADIR on unix-like systems

[Christian Hergert <chergert src gnome org>]

commit cf0511845f653d7eb52e4282a4bdde342f8077de
Author: Christian Hergert <chergert redhat com>
Date:   Tue Jan 11 20:19:49 2022 -0800

    build: only define DATADIR on unix-like systems
    
    Fixes #245

 meson.build | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 872b923d..10eb723f 100644
--- a/meson.build
+++ b/meson.build
@@ -135,7 +135,6 @@ deprecated_c_args = [
 
 config_h = configuration_data()
 config_h.set_quoted('GETTEXT_PACKAGE', package_string)
-config_h.set_quoted('DATADIR', datadir)
 config_h.set_quoted('HICOLORDIR', join_paths(datadir, 'icons/hicolor'))
 config_h.set_quoted('PACKAGE_DATADIR', pkgdatadir)
 config_h.set_quoted('GSV_API_VERSION_S', api_version)
@@ -143,6 +142,10 @@ config_h.set('GSV_API_VERSION', api_version)
 config_h.set('PACKAGE_VERSION', version)
 config_h.set10('ENABLE_FONT_CONFIG', fontconfig_dep.found() and pangoft2_dep.found())
 
+if host_machine.system() != 'windows'
+  config_h.set_quoted('DATADIR', datadir)
+endif
+
 if (version_minor % 2 == 1) or (version_minor >= 90)
   config_h.set10('DEVELOPMENT_BUILD', 1)
 endif