meson: Use gnome module to compile schemas (#1987)

We don't update icon cache here because we don't install any icons to hicolor dir now.

README.md

@@ -6,7 +6,6 @@ A window & compositing manager based on libmutter and designed by elementary for
 ## Building, Testing, and Installation
 
 You'll need the following dependencies:
-* meson
 * gettext (>= 0.19.6)
 * gsettings-desktop-schemas-dev
 * libcanberra-dev
@@ -18,6 +17,7 @@ You'll need the following dependencies:
 * libgtk-3-dev (>= 3.10.0)
 * libmutter-10-dev (>= 42.0) | libmutter-dev (>= 3.18.3)
 * libxml2-utils
+* meson (>= 0.59.0)
 * valac (>= 0.46.0)
 
 Run `meson build` to configure the build environment. Change to the build directory and run `ninja` to build

meson.build

@@ -1,7 +1,7 @@
 project('gala',
     'c', 'vala',
     version: '7.1.3',
-    meson_version: '>= 0.58.0',
+    meson_version: '>= 0.59.0',
     license: 'GPL3',
 )
 
@@ -195,4 +195,7 @@ if vapigen.found()
     subdir('vapi')
 endif
 
-meson.add_install_script('build-aux/meson/post_install.py')
+gnome.post_install(
+    glib_compile_schemas: true,
+    update_desktop_database: true
+)