Roll Flutter Engine from 0e7248d43251 to 4cb3ba7a85f6 (14 revisions) (#140195)

https://github.com/flutter/engine/compare/0e7248d43251...4cb3ba7a85f6

2023-12-15 skia-flutter-autoroll@skia.org Roll Skia from 79f23e8d8b5d to cd2f06086c96 (1 revision) (flutter/engine#49069)
2023-12-15 skia-flutter-autoroll@skia.org Roll Dart SDK from 0471164827b9 to f1e37ed8917e (1 revision) (flutter/engine#49065)
2023-12-15 dnfield@google.com [Impeller] impellerc: delete unused code (flutter/engine#49061)
2023-12-15 30870216+gaaclarke@users.noreply.github.com [Impeller] split out gradient tests from aiks_unittests (flutter/engine#49050)
2023-12-15 30870216+gaaclarke@users.noreply.github.com Revert "[Impeller] Turned on new blur." (flutter/engine#49062)
2023-12-14 matanlurey@users.noreply.github.com Fix header-guard naming convention in `shell/`. (flutter/engine#49006)
2023-12-14 jason-simmons@users.noreply.github.com Manual roll of Dart SDK from a677378ae254 to 0471164827b9 (flutter/engine#49054)
2023-12-14 matanlurey@users.noreply.github.com Rename `font-subset` to `font_subset`. (flutter/engine#49051)
2023-12-14 skia-flutter-autoroll@skia.org Roll Skia from 92935b91193a to 79f23e8d8b5d (1 revision) (flutter/engine#49056)
2023-12-14 chingjun@google.com Suppress warning for the new Activity library. (flutter/engine#49046)
2023-12-14 jonahwilliams@google.com [Impeller] distinguish between no clear color and transparent black clear color. (flutter/engine#49038)
2023-12-14 15619084+vashworth@users.noreply.github.com Unpin mac_toolchain version (flutter/engine#48994)
2023-12-14 30870216+gaaclarke@users.noreply.github.com [Impeller] Turned on new blur. (flutter/engine#48472)
2023-12-14 103135467+sealesj@users.noreply.github.com Remove unused metadata in DEPS from vuln scanning (flutter/engine#48995)

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 jsimmons@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

-0e7248d43251a708e52842a772f9b2415c31a4ea
+4cb3ba7a85f63c01787e67741a0e5e194cf93210