Roll Flutter Engine from c49b861832d3 to 647cf405f3dc (1 revision) (#139598)

https://github.com/flutter/engine/compare/c49b861832d3...647cf405f3dc

2023-12-05 skia-flutter-autoroll@skia.org Roll Dart SDK from 8bfec2c7ed43 to d8efef525ce1 (1 revision) (flutter/engine#48697)

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-engine-flutter-autoroll
Please CC chinmaygarde@google.com,rmistry@google.com,zra@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

bin/internal/engine.version

-c49b861832d3db6a068b0d41b49b4927f2108ed3
+647cf405f3dc3a62ef7abb2dcca08166acdf5200