Explicitly set custom ClassLoader on CGLIB Enhancer

Closes gh-34274

(cherry picked from commit 1b18928bf0)

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassEnhancer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -129,6 +129,9 @@ class ConfigurationClassEnhancer {
 	 */
 	private Enhancer newEnhancer(Class<?> configSuperClass, @Nullable ClassLoader classLoader) {
 		Enhancer enhancer = new Enhancer();
+		if (classLoader != null) {
+			enhancer.setClassLoader(classLoader);
+		}
 		enhancer.setSuperclass(configSuperClass);
 		enhancer.setInterfaces(new Class<?>[] {EnhancedConfiguration.class});
 		enhancer.setUseFactory(false);