26337 Roll Skia from 0ea0e75a3d29 to 8447f13c6d4b (4 revisions) (cla: yes, waiting for tree to go green)

26338 Use the image generator registry & protocol for resolving image decoders. (cla: yes)

26339 Roll Skia from 8447f13c6d4b to ec9d0e865d77 (1 revision) (cla: yes)

26340 Roll Dart SDK from 1c14e29fbfba to 5ae74b9c13b0 (1 revision) (cla: yes, waiting for tree to go green)

26341 Use package:litetest for flutter_frontend_server (cla: yes)

26342 Remove group() support from package:litetest (cla: yes)