Add back a tasty given import

See  #8919

Author: nicolasstucki

tests/run-macros/tasty-tree-map/quoted_1.scala

@@ -5,7 +5,7 @@ object Macros {
   implicit inline def identityMaped[T](x: => T): T = ${ impl('x) }
 
   def impl[T: Type](x: Expr[T])(using qctx: QuoteContext) : Expr[T] = {
-    import qctx.tasty._
+    import qctx.tasty.{_, given _} // FIXME: #8919
     val identityMap = new TreeMap { }
     val transformed = identityMap.transformTerm(x.unseal).seal.cast[T]
     transformed