Deprecate Player#boostElytra (#9899)

The Paper method was chosen for deprecation because it was more
restrictive in that it has an isGliding check.

patches/server/Add-sendOpLevel-API.patch

@@ -36,16 +36,18 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 --- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
 +++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
 @@ -0,0 +0,0 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
-             ? (org.bukkit.entity.Firework) entity.getBukkitEntity()
-             : null;
      }
-+
+     // Paper end
+ 
++    // Paper start - sendOpLevel API
 +    @Override
 +    public void sendOpLevel(byte level) {
 +        Preconditions.checkArgument(level >= 0 && level <= 4, "Level must be within [0, 4]");
 +
 +        this.getHandle().getServer().getPlayerList().sendPlayerPermissionLevel(this.getHandle(), level, false);
 +    }
-     // Paper end
- 
++    // Paper end - sendOpLevel API
++
      @Override
+     public void setCompassTarget(Location loc) {
+         Preconditions.checkArgument(loc != null, "Location cannot be null");