SPIGOT-6508: Rename conflicted getServer

By: md_5 <git@md-5.net>

paper-server/nms-patches/net/minecraft/server/level/EntityTrackerEntry.patch

@@ -102,7 +102,7 @@
 +                org.bukkit.util.Vector velocity = player.getVelocity();
 +
 +                PlayerVelocityEvent event = new PlayerVelocityEvent(player, velocity.clone());
-+                this.entity.level.getServer().getPluginManager().callEvent(event);
++                this.entity.level.getCraftServer().getPluginManager().callEvent(event);
 +
 +                if (event.isCancelled()) {
 +                    cancelled = true;