[vm/ffi] Update package:ffi version

Update package:ffi to a version which does not depend on unpaired
surrogates.

Breaking change in Dart: #41100.

Change-Id: I2a5ba0abee7c6cccb166c234f8f620dbe0063d47
Cq-Include-Trybots: luci.dart.try:vm-ffi-android-debug-arm-try,vm-ffi-android-debug-arm64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/146340
Reviewed-by: Aske Simon Christensen <askesc@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>

DEPS

@@ -91,7 +91,7 @@ vars = {
   "dart_style_tag": "1.3.6",  # Please see the note above before updating.
 
   "dartdoc_tag" : "v0.31.0",
-  "ffi_tag": "ea88d71b043ee14b268c3aedff14e9eb32e20959",
+  "ffi_tag": "4cc14129e81f8804e73321f0ccf5484397a5ddce",
   "fixnum_tag": "eb3748663dc979271ff6a3d014fbe522543b1d91",
   "glob_tag": "e9f4e6b7ae8abe5071461cf8f47191bb19cf7ef6",
   "html_tag": "083a36cd801a4b787ba156b7c6e4c8b2e2daed4a",