Roll Flutter Engine from b867c4da54cc to 494fd7fe85a3 (1 revision) (#133823)

https://github.com/flutter/engine/compare/b867c4da54cc...494fd7fe85a3

2023-08-31 skia-flutter-autoroll@skia.org Roll Skia from e1b27dcecd0a to 818f20f3f653 (2 revisions) (flutter/engine#45353)

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 aaclarke@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://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

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

bin/internal/engine.version

-b867c4da54cc7f5aab511b44e9af95bcc63ff809
+494fd7fe85a30ce4dfc28058961bb71920f514cc