maven(deps): bump com.thoughtworks.xstream:xstream from 1.4.20 to 1.4…

….21 (#4826)

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
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pom.xml

@@ -361,7 +361,7 @@
 			<dependency>
 				<groupId>com.thoughtworks.xstream</groupId>
 				<artifactId>xstream</artifactId>
-				<version>1.4.20</version>
+				<version>1.4.21</version>
 			</dependency>
 			<dependency>
 				<groupId>javax.mail</groupId>