Fix dependency scope for reactor-test

This is a test dependency and should be marked as such.

Fixes gh-8789

spring-boot/pom.xml

@@ -334,6 +334,7 @@
 		<dependency>
 			<groupId>io.projectreactor.addons</groupId>
 			<artifactId>reactor-test</artifactId>
+			<scope>test</scope>
 		</dependency>
 		<dependency>
 			<groupId>org.slf4j</groupId>