Extract spring-boot-test.jar

Relocate the `org.springframework.boot.test` package from the
`spring-boot.jar` to `spring-boot-test.jar`.

Fixes gh-5184

spring-boot-cli/pom.xml

@@ -142,6 +142,18 @@
 			<artifactId>junit</artifactId>
 			<scope>provided</scope>
 		</dependency>
+		<!-- Test -->
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot</artifactId>
+			<type>test-jar</type>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-test</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 	<build>
 		<resources>