ref: test to scala 3 only

src/test/scala/com/raquo/airstream/split/SplittableTypeSpec.scala → src/test/scala-3/com/raquo/airstream/split/SplittableTypeSpec.scala

@@ -9,6 +9,7 @@ import com.raquo.airstream.split.SplittableTypeMacros.{splitMatch, handleCase, t
 import scala.collection.{immutable, mutable}
 import scala.scalajs.js
 import com.raquo.airstream.ShouldSyntax.shouldBeEmpty
+import org.scalatest.{Assertion, Assertions}
 
 class SplittableTypeSpec extends UnitSpec {