Disable TestRestTemplateContextCustomizer after AOT processing

After AOT processing, a TestRestTemplate bean will be defined
directly so the context customizer that initiates its registration is
not needed. We'd already disabled the registrar but this is
insufficient in Graal 22.3 which fails fast when the customizer tries
to reference the registrar.

Fixes gh-32848

Author: wilkinsona

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/web/client/TestRestTemplateContextCustomizer.java

@@ -53,6 +53,9 @@ class TestRestTemplateContextCustomizer implements ContextCustomizer {
 	@Override
 	public void customizeContext(ConfigurableApplicationContext context,
 			MergedContextConfiguration mergedContextConfiguration) {
+		if (AotDetector.useGeneratedArtifacts()) {
+			return;
+		}
 		SpringBootTest springBootTest = TestContextAnnotationUtils
 				.findMergedAnnotation(mergedContextConfiguration.getTestClass(), SpringBootTest.class);
 		if (springBootTest.webEnvironment().isEmbedded()) {

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/web/client/TestRestTemplateContextCustomizerTests.java

@@ -23,6 +23,7 @@
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.test.web.client.TestRestTemplateContextCustomizer.TestRestTemplateRegistrar;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.support.AbstractApplicationContext;
 import org.springframework.test.context.MergedContextConfiguration;
@@ -48,8 +49,10 @@ void whenContextIsNotABeanDefinitionRegistryTestRestTemplateIsRegistered() {
 	@Test
 	void whenUsingAotGeneratedArtifactsTestRestTemplateIsNotRegistered() {
 		new ApplicationContextRunner().withSystemProperties("spring.aot.enabled:true")
-				.withInitializer(this::applyTestRestTemplateContextCustomizer)
-				.run((context) -> assertThat(context).doesNotHaveBean(TestRestTemplate.class));
+				.withInitializer(this::applyTestRestTemplateContextCustomizer).run((context) -> {
+					assertThat(context).doesNotHaveBean(TestRestTemplateRegistrar.class);
+					assertThat(context).doesNotHaveBean(TestRestTemplate.class);
+				});
 	}
 
 	@SuppressWarnings({ "unchecked", "rawtypes" })