MUI Autocomplete onChange: Wrong `value` type

[hofi99]

I noticed that since [this] (#2288) PR, the Autocomplete onChange value parameter is Any.
But actually it should be Any? because clearing the Autocomplete can return null.
This leads to a runtime exception after clearing the Autocomplete component when in the onChange value is specified as Any.

E.g. of failing example

Autocomplete<AutocompleteProps<String>> {
  value = state.value
  onChange = { _, value: Any, _, _ -> // This causes the runtime exception.
    value as String
    setState {
      this.value = value
    }
  }
 // etc.
}

E.g. of working example

Autocomplete<AutocompleteProps<String>> {
  value = state.value
  onChange = { _, value: Any?, _, _ ->
    value as String?
    setState {
      this.value = value
    }
  }
 // etc.
}