defaultVariants as a function

[Kelin2025]

On my current project, some parameters such as colors, sizes etc. can be defined at the upper level
For example

<Field variants={{ size: 'large' }}>
  <Label>...</Label>
  <Input />
</Field>

It's done through React.Context
With that said, it'd be cool to allow defaultVariants to be a function
This way, we can do this:

const Input = withVariants('input', ..., {
  variants: { /* ... */ },
  defaultVariants: {
    size: props => useContext(SizeContext)
  }
})