Fix WelcomePageHandlerMapping order

This commit fixes 220f8cdc and moves the order for
`WelcomePageHandlerMapping` to `2` since the previous order was
conflicting with the resource mapping.

Closes gh-12335

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/WelcomePageHandlerMapping.java

@@ -27,7 +27,6 @@ import org.apache.commons.logging.LogFactory;
 
 import org.springframework.boot.autoconfigure.template.TemplateAvailabilityProviders;
 import org.springframework.context.ApplicationContext;
-import org.springframework.core.Ordered;
 import org.springframework.core.io.Resource;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
@@ -75,7 +74,7 @@ final class WelcomePageHandlerMapping extends AbstractUrlHandlerMapping {
 		ParameterizableViewController controller = new ParameterizableViewController();
 		controller.setViewName(viewName);
 		setRootHandler(controller);
-		setOrder(Ordered.LOWEST_PRECEDENCE - 1);
+		setOrder(2);
 	}
 
 	@Override

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/WelcomePageHandlerMappingTests.java

@@ -35,7 +35,6 @@ import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.core.Ordered;
 import org.springframework.core.io.FileSystemResource;
 import org.springframework.core.io.Resource;
 import org.springframework.http.HttpHeaders;
@@ -70,7 +69,7 @@ public class WelcomePageHandlerMappingTests {
 					WelcomePageHandlerMapping handler = context
 							.getBean(WelcomePageHandlerMapping.class);
 					assertThat(handler.getOrder())
-							.isEqualTo(Ordered.LOWEST_PRECEDENCE - 1);
+							.isEqualTo(2);
 				});
 	}