chore: Set gsettings-desktop-schemas dep to 50.alpha

Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/822>

meson.build

@@ -159,7 +159,7 @@ config_h.set('HAVE_LIBICAL', libical_dep.found())
 assert(cc.has_function('icaltime_days_in_year', dependencies: libical_dep),
        'Error: icaltime_days_in_year() not found in libical!. Upgrade your libical library.')
 
-gsettings_desktop_schemas_dep = dependency('gsettings-desktop-schemas', version: '>= 3.21.2')
+gsettings_desktop_schemas_dep = dependency('gsettings-desktop-schemas', version: '>= 50.alpha')
 libedataserverui_dep = dependency('libedataserverui4-1.0', version: '>= 3.45.1')
 libedataserver_dep = dependency('libedataserver-1.2', version: '>= 3.45.1')
 libecal_dep = dependency('libecal-2.0', version: '>= 3.45.1')

src/meson.build

@@ -19,6 +19,20 @@ gcal_deps = [
 
 built_sources = gnome.mkenums_simple('gcal-enum-types', sources: enum_headers)
 
+#
+# generate type header for gsettings-desktop-schemas
+#
+gdesktop_enums_header = files(
+  gsettings_desktop_schemas_dep.get_variable(pkgconfig: 'prefix') + '/include/gsettings-desktop-schemas/gdesktop-enums.h'
+)
+
+built_sources += gnome.mkenums_simple(
+  'gdesktop-enum-types',
+  sources: gdesktop_enums_header,
+  identifier_prefix: 'GDesktop',
+  symbol_prefix: 'g_desktop'
+)
+
 built_sources += gnome.gdbus_codegen(
   'gcal-shell-search-provider-generated',
   shell_search_provider_dbus_interfaces,