Add factory for NoopTracer instead of using instance supplier

Closes gh-33298

spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/actuate/observability/ObservabilityContextCustomizerFactory.java

@@ -26,6 +26,7 @@ import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
 import org.springframework.beans.factory.BeanFactoryUtils;
+import org.springframework.beans.factory.FactoryBean;
 import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
@@ -133,7 +134,7 @@ class ObservabilityContextCustomizerFactory implements ContextCustomizerFactory
 	 * {@link ConfigurationClassPostProcessor} and adds a {@link Tracer} bean definition
 	 * when a {@link Tracer} hasn't already been registered.
 	 */
-	private static class NoopTracerRegistrar implements BeanDefinitionRegistryPostProcessor, Ordered, BeanFactoryAware {
+	static class NoopTracerRegistrar implements BeanDefinitionRegistryPostProcessor, Ordered, BeanFactoryAware {
 
 		private BeanFactory beanFactory;
 
@@ -154,7 +155,7 @@ class ObservabilityContextCustomizerFactory implements ContextCustomizerFactory
 			}
 			if (BeanFactoryUtils.beanNamesForTypeIncludingAncestors((ListableBeanFactory) this.beanFactory,
 					Tracer.class, false, false).length == 0) {
-				registry.registerBeanDefinition("noopTracer", new RootBeanDefinition(Tracer.class, () -> Tracer.NOOP));
+				registry.registerBeanDefinition("noopTracer", new RootBeanDefinition(NoopTracerFactoryBean.class));
 			}
 		}
 
@@ -164,4 +165,18 @@ class ObservabilityContextCustomizerFactory implements ContextCustomizerFactory
 
 	}
 
+	static class NoopTracerFactoryBean implements FactoryBean<Tracer> {
+
+		@Override
+		public Tracer getObject() {
+			return Tracer.NOOP;
+		}
+
+		@Override
+		public Class<?> getObjectType() {
+			return Tracer.class;
+		}
+
+	}
+
 }