Duplicate deletion commit

Thanks for your blog and code sharing, Didact is awesome!

I got an issue here when I tried to delete several siblings in the same time.

Lines 124 to 129 in a127ff4

    
           } else if (fiber.effectTag === "DELETION") { 
        
             commitDeletion(fiber, domParent) 
        
           } 
        
           commitWork(fiber.child) 
        
           commitWork(fiber.sibling)

In this line, after one fiber gets deleted, its sibling will commitWork next, which has been already registered in deletions.

As a result, some fiber will be deleted more than once (after its sibling and in deletions.forEach), which will cause an error.

	} else if (fiber.effectTag === "DELETION") {
	commitDeletion(fiber, domParent)
	}

	commitWork(fiber.child)
	commitWork(fiber.sibling)