Downloaded LWJGL libraries

- LWJGL is no longer shaded into the Bukkit jar
- plugin.yml lists the LWJGL jars and Linux natives as Spigot libraries
- The Paper loader resolves the same plugin.yml list through the Maven Central mirror
- The packed payload no longer reserves the LWJGL natives prefix
- Tests cover reading the library list from the plugin jar

adapters/bukkit/plugin/src/test/java/art/arcane/iris/IrisPluginLoaderTest.java

@@ -4,9 +4,13 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
+import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.List;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
 
 import static org.junit.Assert.assertEquals;
 
@@ -31,4 +35,19 @@ public class IrisPluginLoaderTest {
 
         assertEquals(List.of(relocatedCaffeine, relocatedGson), libraries);
     }
+
+    @Test
+    public void readsMavenLibrariesFromTheSpigotDescriptorInThePluginJar() throws Exception {
+        Path jar = temporaryFolder.getRoot().toPath().resolve("Iris.jar");
+        try (OutputStream file = Files.newOutputStream(jar); ZipOutputStream zip = new ZipOutputStream(file)) {
+            zip.putNextEntry(new ZipEntry("plugin.yml"));
+            zip.write("name: Iris\nlibraries: [ 'org.lwjgl:lwjgl:3.4.3', 'org.lwjgl:lwjgl:jar:natives-linux:3.4.3' ]\n"
+                    .getBytes(StandardCharsets.UTF_8));
+            zip.closeEntry();
+        }
+
+        List<String> libraries = IrisPluginLoader.mavenLibraries(jar);
+
+        assertEquals(List.of("org.lwjgl:lwjgl:3.4.3", "org.lwjgl:lwjgl:jar:natives-linux:3.4.3"), libraries);
+    }
 }