Roll Flutter Engine from b57c899aefd7 to 70c45157c60a (1 revision) (#141125)

https://github.com/flutter/engine/compare/b57c899aefd7...70c45157c60a

2024-01-08 30870216+gaaclarke@users.noreply.github.com [Impeller] new blur: chop off blur extremities (flutter/engine#49574)

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 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

-b57c899aefd7b76a02c3649ea65c174791516c59
+70c45157c60a799c12466836fca50205591e97bb