Fix #974 – Scala 3 macro cannot find Writes for Seq[Map[String, T]] (#…

…993)

Moved the deprecated method `DefaultWrites.mapWrites` into `LowPriorityWrites` to get rid of the ambiguity.

play-json/shared/src/main/scala/play/api/libs/json/Writes.scala

@@ -366,7 +366,7 @@ trait DefaultWrites extends LowPriorityWrites with EnumerationWrites {
    * Serializer for Map[String,V] types.
    */
   @deprecated("Use `genericMapWrites`", "2.8.0")
-  implicit def mapWrites[V: Writes]: OWrites[MapWrites.Map[String, V]] = MapWrites.mapWrites
+  def mapWrites[V: Writes]: OWrites[MapWrites.Map[String, V]] = MapWrites.mapWrites
 
   implicit def keyMapWrites[K: KeyWrites, V: Writes, M[K, V] <: MapWrites.Map[K, V]]: OWrites[M[K, V]] = {
     val kw = implicitly[KeyWrites[K]]

play-json/shared/src/test/scala/play/api/libs/json/WritesSharedSpec.scala

@@ -84,6 +84,10 @@ final class WritesSharedSpec extends AnyWordSpec with Matchers {
     "write lazy maps" in {
       Json.toJson(Map("a" -> 1).map(kv => kv._1 -> (kv._2 + 1))).mustEqual(Json.obj("a" -> 2))
     }
+
+    "write a map nested in a seq" in {
+      Json.toJson(Seq(Map("a" -> 1))).mustEqual(Json.arr(Json.obj("a" -> 1)))
+    }
   }
 
   "Iterable writes" should {