Bump com.thoughtworks.xstream:xstream from 1.4.20 to 1.4.21

Bumps [com.thoughtworks.xstream:xstream](https://github.com/x-stream/xstream) from 1.4.20 to 1.4.21.
- [Release notes](https://github.com/x-stream/xstream/releases)
- [Commits](https://github.com/x-stream/xstream/commits)

---
updated-dependencies:
- dependency-name: com.thoughtworks.xstream:xstream
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -186,7 +186,7 @@
         <cs.winrm4j.version>0.5.0</cs.winrm4j.version>
         <cs.xapi.version>6.2.0-3.1</cs.xapi.version>
         <cs.xmlrpc.version>3.1.3</cs.xmlrpc.version>
-        <cs.xstream.version>1.4.20</cs.xstream.version>
+        <cs.xstream.version>1.4.21</cs.xstream.version>
         <org.springframework.version>5.3.26</org.springframework.version>
         <cs.ini.version>0.5.4</cs.ini.version>
         <cs.caffeine.version>3.1.7</cs.caffeine.version>