Properly remove Spock from spring-boot-dependencies

See gh-9043

spring-boot-dependencies/pom.xml

@@ -2046,22 +2046,6 @@
 				<artifactId>slf4j-simple</artifactId>
 				<version>${slf4j.version}</version>
 			</dependency>
-			<dependency>
-				<groupId>org.spockframework</groupId>
-				<artifactId>spock-core</artifactId>
-				<version>${spock.version}</version>
-				<exclusions>
-					<exclusion>
-						<groupId>org.codehaus.groovy</groupId>
-						<artifactId>groovy-all</artifactId>
-					</exclusion>
-				</exclusions>
-			</dependency>
-			<dependency>
-				<groupId>org.spockframework</groupId>
-				<artifactId>spock-spring</artifactId>
-				<version>${spock.version}</version>
-			</dependency>
 			<dependency>
 				<groupId>org.springframework</groupId>
 				<artifactId>spring-core</artifactId>