No longer use CraftBukkit to get the player's ping, and instead use the Player's spigot object.

pom.xml

@@ -22,13 +22,6 @@
 			<artifactId>ProtocolLib</artifactId>
 			<version>4.4.0</version>
         </dependency>
-        <dependency>
-            <groupId>org.bukkit</groupId>
-            <artifactId>craftbukkit</artifactId>
-            <version>LATEST</version>
-            <scope>system</scope>
-            <systemPath>${project.basedir}/tools/craftbukkit.jar</systemPath>
-        </dependency>
 	</dependencies>
 
 	<repositories>

src/main/java/pw/kaboom/extras/commands/CommandPing.java

@@ -4,14 +4,13 @@ import org.bukkit.ChatColor;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
-import org.bukkit.craftbukkit.v1_16_R3.entity.CraftPlayer;
 import org.bukkit.entity.Player;
 
 public final class CommandPing implements CommandExecutor {
 
     public boolean onCommand(final CommandSender sender, final Command command, final String label, final String[] args) {
         final Player player = (Player) sender;
-        final int ping = ((CraftPlayer) player).getHandle().playerConnection.player.ping;
+        final int ping = player.spigot().getPing();
         final int d = (int) Math.floor(ping / 100);
         ChatColor highlighting = ChatColor.WHITE;