Roll Fuchsia GN SDK from ALNKvSVWQSpw1uxPy... to OKGFjciA5Vd0TQks4... (…

…flutter#54840)

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/fuchsia-gn-sdk-flutter-engine
Please CC chrome-fuchsia-engprod@google.com,matanl@google.com on the revert to ensure that a human
is aware of the problem.

To file a bug in Flutter: https://github.com/flutter/flutter/issues/new/choose

To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

DEPS

@@ -258,7 +258,7 @@ vars = {
 
  # The version / instance id of the cipd:chromium/fuchsia/gn-sdk which will be
  # used altogether with fuchsia-sdk to generate gn based build rules.
- 'fuchsia_gn_sdk_version': 'ALNKvSVWQSpw1uxPyh6OvWHf878FzEm6nvVEyTB8H-8C',
+ 'fuchsia_gn_sdk_version': 'OKGFjciA5Vd0TQks4ow7-ppfxy_Y6v5hSjjn2w6LWjwC',
 }
 
 gclient_gn_args_file = 'src/flutter/third_party/dart/build/config/gclient_args.gni'