Remove unused Opt-In annotation

Author: PatilShreyas

permission-flow/src/main/java/dev/shreyaspatil/permissionFlow/watchmen/PermissionWatchmen.kt

@@ -128,7 +128,6 @@ internal class PermissionWatchmen(
      * going in settings) and recalculates state of the permissions which are currently being
      * observed.
      */
-    @OptIn(FlowPreview::class)
     private fun watchActivities() {
         if (watchActivityEventJob != null && watchActivityEventJob?.isActive == true) return
         watchActivityEventJob =