fix: Add version for cyclonedx-maven-plugin

Author: hzpz

spring-boot-admin-samples/spring-boot-admin-sample-servlet/pom.xml

@@ -92,6 +92,7 @@
             <plugin>
                 <groupId>org.cyclonedx</groupId>
                 <artifactId>cyclonedx-maven-plugin</artifactId>
+                <version>2.8.1</version>
                 <executions>
                     <execution>
                         <phase>validate</phase>