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/Custom-Chat-Completion-Suggestions-API.patch

@@ -9,10 +9,10 @@ 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 {
- 
-         this.getHandle().getServer().getPlayerList().sendPlayerPermissionLevel(this.getHandle(), level, false);
      }
-+
+     // Paper end - sendOpLevel API
+ 
++    // Paper start - custom chat completions API
 +    @Override
 +    public void addAdditionalChatCompletions(@NotNull Collection<String> completions) {
 +        this.getHandle().connection.send(new net.minecraft.network.protocol.game.ClientboundCustomChatCompletionsPacket(
@@ -28,6 +28,8 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +            new ArrayList<>(completions)
 +        ));
 +    }
-     // Paper end
- 
++    // Paper end - custom chat completions API
++
      @Override
+     public void setCompassTarget(Location loc) {
+         Preconditions.checkArgument(loc != null, "Location cannot be null");