7649 Fix two typos in embedder docs (cla: yes)

7651 Add FlutterProjectArgs::root_isolate_create_callback (cla: yes)

7658 Use the Wuffs GIF decoder (cla: yes)

7659 DCHECK that clip layer’s behavior isn’t none (cla: yes)

7660 Add kernel-worker and dart2js to BUILD.gn (cla: yes)

7678 Move Brightness definition to dart:ui (#27479) (cla: yes)

7686 Replace hb_face_reference_table with hb_ot_color_has_png in isColorBitmapFont (cla: yes)

7687 Lower the threshold to raster cache pictures (cla: yes)