Roll Flutter Engine from d4698c65aa8d to 496ef6a9c277 (6 revisions) (#134569)

https://github.com/flutter/engine/compare/d4698c65aa8d...496ef6a9c277

2023-09-12 skia-flutter-autoroll@skia.org Roll Skia from 7cafb622ee7f to a4f8f5177c8b (1 revision) (flutter/engine#45719)
2023-09-12 skia-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from vGleXqh2SRUNJM7JN... to MWWrSP9mSVlGIOaDo... (flutter/engine#45718)
2023-09-12 skia-flutter-autoroll@skia.org Roll Skia from 438ec87ea2be to 7cafb622ee7f (1 revision) (flutter/engine#45716)
2023-09-12 matanlurey@users.noreply.github.com [Impeller] Make `CreateMockVulkanContext()` thread-safe (flutter/engine#45687)
2023-09-12 30870216+gaaclarke@users.noreply.github.com [Impeller] moved validation layers on by default logic to gni scripts (flutter/engine#45682)
2023-09-12 skia-flutter-autoroll@skia.org Roll Skia from f3f0cab7efd0 to 438ec87ea2be (1 revision) (flutter/engine#45714)

Also rolling transitive DEPS:
  fuchsia/sdk/core/linux-amd64 from vGleXqh2SRUN to MWWrSP9mSVlG

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 bdero@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

-d4698c65aa8d9e42d4aa70391c804270506a5f82
+496ef6a9c277e5572fa4350a50ff140816c73845

bin/internal/fuchsia-linux.version

-vGleXqh2SRUNJM7JNwpEoinm9VFaEF4eIgBF0M_-V9sC
+MWWrSP9mSVlGIOaDoAhSNSx_v1fGNKJtHenmI0aa4IAC