Fix build due to spigot changing the build timestamp process

Spigot-Server-Patches/POM-Changes.patch

@@ -156,6 +156,19 @@ index 9fc92e347f..6cc18aa360 100644
                  <dependencies>
                      <!-- we need our custom version as it fixes some bugs on case sensitive file systems -->
                      <dependency>
+diff --git a/src/main/java/org/bukkit/craftbukkit/Main.java b/src/main/java/org/bukkit/craftbukkit/Main.java
+index 88223a53cb..cb5d0f5378 100644
+--- a/src/main/java/org/bukkit/craftbukkit/Main.java
++++ b/src/main/java/org/bukkit/craftbukkit/Main.java
+@@ -0,0 +0,0 @@ public class Main {
+                 }
+ 
+                 if (Main.class.getPackage().getImplementationVendor() != null && System.getProperty("IReallyKnowWhatIAmDoingISwear") == null) {
+-                    Date buildDate = new Date(Integer.parseInt(Main.class.getPackage().getImplementationVendor()) * 1000L);
++                    Date buildDate = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'").parse(Main.class.getPackage().getImplementationVendor()); // Paper
+ 
+                     Calendar deadline = Calendar.getInstance();
+                     deadline.add(Calendar.DAY_OF_YEAR, -21);
 diff --git a/src/main/java/org/bukkit/craftbukkit/util/Versioning.java b/src/main/java/org/bukkit/craftbukkit/util/Versioning.java
 index 93046379d0..674096cab1 100644
 --- a/src/main/java/org/bukkit/craftbukkit/util/Versioning.java