graphite: Update to latest Git, switch to MIT license

Graphite is now available under:
MIT OR MPL-2.0 OR LGPL-2.1-or-later OR GPL-2.0-or-later

We pick MIT which is the same as Godot's main license for simplicity.

Remove define to skip deprecation warnings, upstream fixed those.

modules/text_server_adv/SCsub

@@ -223,9 +223,6 @@ if env["builtin_graphite"] and freetype_enabled and env["graphite"]:
         ]
     )
 
-    if env.msvc:  # Not our business to fix.
-        env_graphite.Append(CCFLAGS=["-D_SILENCE_ALL_CXX17_DEPRECATION_WARNINGS"])
-
     lib = env_graphite.add_library("graphite_builtin", thirdparty_sources)
     thirdparty_obj += lib