feat(paper): remove mention of deprecated teleport flag (#689)

* feat(paper): remove mention of deprecated teleport flag

Took 6 minutes

* Add again but mention not need to use

Took 7 minutes

* Better explanation

Co-authored-by: Matouš Kučera <mk@kcra.me>

---------

Co-authored-by: Matouš Kučera <mk@kcra.me>

Author: Doc94

src/content/docs/paper/dev/api/entity-api/entity-teleport.md

@@ -2,6 +2,7 @@
 title: Teleportation
 description: The entity teleportation API and how to use it.
 slug: paper/dev/entity-teleport
+version: 1.21.10
 ---
 
 Entities can be instantaneously teleported to specific positions, synchronously and asynchronously with the
@@ -76,6 +77,12 @@ player.teleport(
 
 ### Retaining passengers
 
+:::caution[Warning]
+
+Since 1.21.10, this flag does not do anything, as it's been made the default behavior when teleporting entities.
+
+:::
+
 Teleport an entity with the [`RETAIN_PASSENGERS`](jd:paper:io.papermc.paper.entity.TeleportFlag$EntityState#RETAIN_PASSENGERS) flag,
 allowing its passengers to be transferred with the entity.