Removed `Finalizer`s from the unsupported features by dart:ffi
Removed `Finalizer`s from the unsupported features by dart:ffi

Closes https://github.com/dart-lang/sdk/pull/50488

GitOrigin-RevId: 68cd56758359b2cedc604c615ba46b344a1af50d
Change-Id: Ie892c676578230d99972bfe3d1546e8609096993
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/270223
Commit-Queue: Daco Harkes <930cbae0ca77f1954c53e32620d89cfcca318f00@google.com>
Reviewed-by: Daco Harkes <930cbae0ca77f1954c53e32620d89cfcca318f00@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk