Roll Flutter Engine from f71e5ad8586b to a396dc1a03a9 (3 revisions) (#145928)

https://github.com/flutter/engine/compare/f71e5ad8586b...a396dc1a03a9

2024-03-28 jacksongardner@google.com [skwasm] Use text position affinity when calculating word boundaries. (flutter/engine#51753)
2024-03-28 mdebbar@google.com Prevent `solo: true` from being committed (flutter/engine#51712)
2024-03-28 skia-flutter-autoroll@skia.org Manual roll Dart SDK from 291217c1d399 to bb65648e20e2 (3 revisions) (flutter/engine#51755)

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 jacksongardner@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

-f71e5ad8586bb9ad60107a71f60b23981f6de67a
+a396dc1a03a91222170e29e21f5e54c9410372e9