Sequencer strips does not sync in `132-fix-undo-edit-last-operation-redo-handling-2 branch`

Summary

Sequencer isn't sync in 132-fix-undo-edit-last-operation-redo-handling-2

• Addon version: 132-fix-undo-edit-last-operation-redo-handling-2
• Blender version: 2.91.0
• OS: all

Possible fixes

Merge bl_sequencer implementation into bl_scene.