Update paperweight to 2.0.0-beta.8 and remove deprecated VM arg from runs

paper-server/build.gradle.kts

@@ -271,7 +271,7 @@ fun TaskContainer.registerRunTask(
         languageVersion.set(JavaLanguageVersion.of(21))
         vendor.set(JvmVendorSpec.JETBRAINS)
     })
-    jvmArgs("-XX:+AllowEnhancedClassRedefinition", "-XX:+AllowRedefinitionToAddDeleteMethods")
+    jvmArgs("-XX:+AllowEnhancedClassRedefinition")
 
     if (rootProject.childProjects["test-plugin"] != null) {
         val testPluginJar = rootProject.project(":test-plugin").tasks.jar.flatMap { it.archiveFile }