10268 [fuchsia] Make cirrus build fuchsia artifacts (cla: yes)

10273 Remove one last final call to AddPart() (cla: yes)

10282 Export FFI from sky_engine. (cla: yes)

10293 Add fuchsia.stamp for roller (cla: yes)

10294 Roll src/third_party/dart 80c4954d4d..bd049f5b53 (37 commits) (cla: yes)

10295 Fix memory overrun in minikin patch (cla: yes, crash)

10296 fix CI (cla: yes)

10297 Ensure that the SingleFrameCodec stays alive until the ImageDecoder invokes its callback (cla: yes)