Register JarUrlClassLoader as parallel capable

See gh-41665

Author: Rajin9601

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/net/protocol/jar/JarUrlClassLoader.java

@@ -40,6 +40,10 @@
  */
 public abstract class JarUrlClassLoader extends URLClassLoader {
 
+	static {
+		ClassLoader.registerAsParallelCapable();
+	}
+
 	private final URL[] urls;
 
 	private final boolean hasJarUrls;