Remove obsolete @OptIn(ExperimentalStdlibApi::class) annotations

They were added when `buildList`, `buildMap` and `buildSet` were experimental.

^KT-62510

core/compiler.common/src/org/jetbrains/kotlin/descriptors/Visibilities.kt

@@ -52,7 +52,6 @@ object Visibilities {
         }
     }
 
-    @OptIn(ExperimentalStdlibApi::class)
     private val ORDERED_VISIBILITIES: Map<Visibility, Int> = buildMap {
         put(PrivateToThis, 0)
         put(Private, 0)