update scala-native in Scala 3 migration guide

[xuwei-k]

docs.scala-lang/_overviews/scala3-migration/tutorial-prerequisites.md

Lines 104 to 107 in 588c5b6

	Scala 3 does not yet support [Scala Native](https://scala-native.readthedocs.io/en/latest/).
	If you project is cross-built to Scala Native, you can port it to Scala 3.
	But you will not be able to compile for the Native platform.

https://scala-native.readthedocs.io/en/latest/changelog/0.4.3.html

We’re happy to announce the release of Scala Native v0.4.3, which brings support for Scala 3!