Roll Flutter Engine from 8b7cdb02f7f3 to 609f9d536494 (1 revision) (#125097)

https://github.com/flutter/engine/compare/8b7cdb02f7f3...609f9d536494

2023-04-19 bdero@google.com [Impeller] Add buffer-to-texture blit capability check; fix GL+VK playgrounds on macOS (flutter/engine#41320)

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 chinmaygarde@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

-8b7cdb02f7f36cac7f1c3fc3e08af880f6d67b3a
+609f9d536494220270afc5349f1868aa4b35be27