Roll Flutter Engine from e9178e115f14 to 2e6b1e6c3458 (1 revision) (#127196)

https://github.com/flutter/engine/compare/e9178e115f14...2e6b1e6c3458

2023-05-19 mdebbar@google.com [web] Cleanup Vector3 (flutter/engine#42096)

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://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

-e9178e115f14509c9f4f55fc1ef73d5bccbf5be4
+2e6b1e6c345882f871812b369fe20b1a4343d598