Remove wall-time / unused skip tick protection (#11412)

Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.

patches/server/0980-Configurable-damage-tick-when-blocking-with-shield.patch

@@ -0,0 +1,19 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Bjarne Koll <lynxplay101@gmail.com>
+Date: Thu, 13 Jun 2024 17:16:01 +0200
+Subject: [PATCH] Configurable damage tick when blocking with shield
+
+
+diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
+index 7b6d067eb8b22a8e0a82a2969c92ba243230733a..5f1c585c819d25319a4fefd30abde3de7620cf6d 100644
+--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
++++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
+@@ -2411,7 +2411,7 @@ public abstract class LivingEntity extends Entity implements Attackable {
+                         CriteriaTriggers.PLAYER_HURT_ENTITY.trigger((ServerPlayer) damagesource.getEntity(), this, damagesource, originalDamage, f, true); // Paper - fix taken/dealt param order
+                     }
+ 
+-                    return true;
++                    return !io.papermc.paper.configuration.GlobalConfiguration.get().unsupportedSettings.skipVanillaDamageTickWhenShieldBlocked; // Paper - this should always return true, however expose an unsupported setting to flip this to false to enable "shield stunning".
+                 } else {
+                     return true; // Paper - return false ONLY if event was cancelled
+                 }