fix(deps): update dependency com.thoughtworks.xstream:xstream to v1.4.21 [security]

Author: renovate[bot]

gradle/libs.versions.toml

@@ -213,7 +213,7 @@ velocity-engine-core = { module = "org.apache.velocity:velocity-engine-core", ve
 velocity-tools-generic = { module = "org.apache.velocity.tools:velocity-tools-generic", version = "3.1" }
 xmpbox = { module = "org.apache.pdfbox:xmpbox", version = "2.0.24" }
 xpp3 = { module = "xpp3:xpp3", version = "1.1.4c" }
-xstream = { module = "com.thoughtworks.xstream:xstream", version = "1.4.20" }
+xstream = { module = "com.thoughtworks.xstream:xstream", version = "1.4.21" }
 jsch = { module = "com.github.mwiede:jsch", version = "2.27.7" }
 postgresql = { module = "org.postgresql:postgresql", version = "42.7.12" }
 snakeyaml = { module = "org.yaml:snakeyaml", version = "2.5" }