Updated Upstream (Bukkit/CraftBukkit)

Upstream has released updates that appear to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Bukkit Changes:
304e83eb PR-1002: Improve documentation and implementation of getMaxStackSize
e8215ea2 SPIGOT-7638: Library loader does not seem to resolve every dependency
79c595c0 SPIGOT-7637: Bad logic in checking nullability of AttributeModifier slots

CraftBukkit Changes:
91b1fc3f1 SPIGOT-7644: Fix ItemMeta#getAsString
4e77a81e1 SPIGOT-7615: PlayerLeashEntityEvent cancelled eats lead
996f660f3 Do not remove leash knot if leasing to an existing leash knot gets cancelled
f70367d42 SPIGOT-7643: Fix inverted leash event cancelled usage and remove leash knot if no entity gets leashed
7ddb48294 SPIGOT-7640: Abnormal jumping height of wind charge
080c8711e SPIGOT-7639: Incoming plugin channels not working
ad549847e Open a direct connection instead of pinging mojang server to check if it is reachable
38e2926c5 SPIGOT-7365: DamageCause blocked by shield should trigger invulnerableTime

patches/api/0456-ItemStack-Tooltip-API.patch

@@ -119,10 +119,10 @@ index 7e6bdf3333537491b3421d196779a4eb502f7314..a3ba9249e636d1fb8dad98fab4134360
 +    @NotNull java.util.List<net.kyori.adventure.text.Component> computeTooltipLines(@NotNull ItemStack itemStack, @NotNull io.papermc.paper.inventory.tooltip.TooltipContext tooltipContext, @Nullable org.bukkit.entity.Player player); // Paper - expose itemstack tooltip lines
  }
 diff --git a/src/main/java/org/bukkit/inventory/ItemStack.java b/src/main/java/org/bukkit/inventory/ItemStack.java
-index 0611f19bcdd8230b439b5055713221318dce98e2..9440cffffa1d7e75d2d76d55d5608bafd69b645b 100644
+index a1d0e479b9f28378f858f86ba8b0e9b7ddf71446..b669df4bd1ff0ecba575d42415973e81bccddbbe 100644
 --- a/src/main/java/org/bukkit/inventory/ItemStack.java
 +++ b/src/main/java/org/bukkit/inventory/ItemStack.java
-@@ -1018,4 +1018,21 @@ public class ItemStack implements Cloneable, ConfigurationSerializable, Translat
+@@ -1021,4 +1021,21 @@ public class ItemStack implements Cloneable, ConfigurationSerializable, Translat
          return type.isAir() || amount <= 0;
      }
      // Paper end