dd24949ca Adds package:litetest, uses it instead of package:test under testing/dart (flutter/engine#26215) (#82992)

FlutterDriver: deprecate enableAccessibility; redirect it to setSemantics; add setSemantics tests (#82939)

* deprecate enableAccessibility; redirect it to setSemantics
Co-authored-by: David Iglesias <ditman@gmail.com>

This reverts commit e86f9c7a.

This is a re-application of https://github.com/flutter/flutter/pull/81884,
but with https://github.com/flutter/flutter/pull/82834 landed first.

Fixes https://github.com/flutter/flutter/issues/81883