Ensure that children exists

[alexpchin]

In createCollapsibleTabs, we should ensure that children exists as this can be undefined:

Line 88:

const scrollY = useSharedValue([...new Array(children.length)].map(() => 0));

Line 106:

const [data] = React.useState(
  [...new Array(children.length)].map((_, i) => i)
)

[alexpchin]

Addressed in: #69