Roll Flutter Engine from bc5bbd3b9ebe to a7f2267dd1f4 (1 revision) (#138459)

https://github.com/flutter/engine/compare/bc5bbd3b9ebe...a7f2267dd1f4

2023-11-15 chris@bracken.jp [macOS] Clean up allocations in key responder tests (flutter/engine#48048)

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 jonahwilliams@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

-bc5bbd3b9ebeefc9d92fd657607f9509ad709daa
+a7f2267dd1f485fb38b462953c574c51ab3f546c