[ffigen] bump package:ffi (#394)

diff --git a/pkgs/ffigen/pubspec.yaml b/pkgs/ffigen/pubspec.yaml
index 51050c2..d1345f9 100644
--- a/pkgs/ffigen/pubspec.yaml
+++ b/pkgs/ffigen/pubspec.yaml
@@ -11,7 +11,7 @@
   sdk: '>=2.17.0 <3.0.0'
 
 dependencies:
-  ffi: ^1.2.1
+  ffi: ^2.0.0
   yaml: ^3.0.0
   path: ^1.8.0
   quiver: ^3.0.0