chore: bump dart-sdk to 12401cce210d164318a7becd9742abfe8391538f

Author: bdero

DEPS

@@ -16,7 +16,7 @@ vars = {
   'skia_git': 'https://skia.googlesource.com',
   'llvm_git': 'https://llvm.googlesource.com',
   'skia_revision': '837be28dd21818d2169e1e6789e89e771a55f01d',
-  "dart_sdk_revision": "fc0de217def061c060a0dd6e42ff98428b18e52e",
+  "dart_sdk_revision": "12401cce210d164318a7becd9742abfe8391538f",
   "dart_sdk_git": "git@github.com:shorebirdtech/dart-sdk.git",
   "updater_git": "https://github.com/shorebirdtech/updater.git",
   "updater_rev": "8691c8f60e69f8eb1f35361f4a22e8c9a7fdf93c",