Updated Upstream (Bukkit/CraftBukkit/Spigot)

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

Please note that this build includes changes to meet upstreams
requirements for nullability annotations. While we aim for a level of
accuracy, these might not be 100% correct, if there are any issues,
please speak to us on discord, or open an issue on the tracker to
discuss.

Bukkit Changes:
9a6a1de3 Remove nullability annotations from enum constructors
3f0591ea SPIGOT-2540: Add nullability annotations to entire Bukkit API

CraftBukkit Changes:
8d8475fc SPIGOT-4666: Force parameter in HumanEntity#sleep
8b1588e2 Fix ExplosionPrimeEvent#setFire not working with EnderCrystals
39a287b7 Don't ignore newlines in PlayerListHeader/Footer

Spigot Changes:
cf694d87 Add nullability annotations

Spigot-API-Patches/Add-sender-name-to-commands.yml-replacement.patch

@@ -7,19 +7,18 @@ This allows you to use $sender in commands.yml definitions to make
 commands that auto target self.
 
 diff --git a/src/main/java/org/bukkit/command/FormattedCommandAlias.java b/src/main/java/org/bukkit/command/FormattedCommandAlias.java
-index 9c80f464..631be1cb 100644
+index 982f0fb4..3276879d 100644
 --- a/src/main/java/org/bukkit/command/FormattedCommandAlias.java
 +++ b/src/main/java/org/bukkit/command/FormattedCommandAlias.java
 @@ -0,0 +0,0 @@
  package org.bukkit.command;
  
  import java.util.ArrayList;
-+import java.util.logging.Level;
-+import java.util.regex.Matcher;
-+import java.util.regex.Pattern;
++import java.util.regex.Matcher; // Paper
++import java.util.regex.Pattern; // Paper
  
  import org.bukkit.Bukkit;
- 
+ import org.jetbrains.annotations.NotNull;
 @@ -0,0 +0,0 @@ public class FormattedCommandAlias extends Command {
          ArrayList<String> commands = new ArrayList<String>();
          for (String formatString : formatStrings) {
@@ -33,8 +32,8 @@ index 9c80f464..631be1cb 100644
          return result;
      }
  
--    private String buildCommand(String formatString, String[] args) {
-+    private String buildCommand(CommandSender sender, String formatString, String[] args) { // Paper
+-    private String buildCommand(@NotNull String formatString, @NotNull String[] args) {
++    private String buildCommand(@NotNull CommandSender sender, @NotNull String formatString, @NotNull String[] args) { // Paper
 +        if (formatString.contains("$sender")) { // Paper
 +            formatString = formatString.replaceAll(Pattern.quote("$sender"), Matcher.quoteReplacement(sender.getName())); // Paper
 +        } // Paper