Use ClassLoader for method or field in MergedAnnotation

Prior to this commit, the `return` keyword was missing in
TypeMappedAnnotation's getClassLoader() implementation, which prevented
the ClassLoader of the Member (Method or Field) from being used.

This commit fixes that by adding the missing `return` keyword and adds
a test using a custom ClassLoader to verify the correct behavior.

Closes gh-36606

(cherry picked from commit f3b6c222f9)

spring-core/src/main/java/org/springframework/core/annotation/TypeMappedAnnotation.java

@@ -595,7 +595,7 @@ final class TypeMappedAnnotation<A extends Annotation> extends AbstractMergedAnn
 				return clazz.getClassLoader();
 			}
 			if (this.source instanceof Member member) {
-				member.getDeclaringClass().getClassLoader();
+				return member.getDeclaringClass().getClassLoader();
 			}
 		}
 		return null;

spring-core/src/test/java/org/springframework/core/annotation/TypeMappedAnnotationTests.java

@@ -20,12 +20,15 @@ import java.io.InputStream;
 import java.lang.annotation.Annotation;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import java.lang.reflect.Method;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.core.OverridingClassLoader;
+
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
@@ -109,6 +112,23 @@ class TypeMappedAnnotationTests {
 		assertThat(annotation.getClass("classValue")).isEqualTo(InputStream.class);
 	}
 
+	@Test  // gh-36606
+	void adaptFromStringToClassWithMemberSourceUsesMemberClassLoader() throws Exception {
+		OverridingClassLoader classLoader = new OverridingClassLoader(getClass().getClassLoader()) {
+			@Override
+			protected boolean isEligibleForOverriding(String className) {
+				return ClassAttributes.class.getName().equals(className);
+			}
+		};
+		Class<?> sourceClass = classLoader.loadClass(ClassAttributes.class.getName());
+		Method sourceMethod = sourceClass.getDeclaredMethod("classValue");
+
+		MergedAnnotation<?> annotation = TypeMappedAnnotation.of(null, sourceMethod,
+				ClassAttributes.class, Map.of("classValue", sourceClass.getName()));
+
+		assertThat(annotation.getClass("classValue").getClassLoader()).isSameAs(classLoader);
+	}
+
 	@Test
 	void adaptFromStringArrayToClassArray() {
 		MergedAnnotation<?> annotation = TypeMappedAnnotation.of(null, null, ClassAttributes.class,