Update versions-maven-plugin.version to v2.21.0

Author: renovate[bot]

pom.xml

@@ -51,7 +51,7 @@
 		<maven.compiler.source>1.8</maven.compiler.source>
 
 		<!-- Maven Central Release tools -->
-		<versions-maven-plugin.version>2.19.1</versions-maven-plugin.version>
+		<versions-maven-plugin.version>2.21.0</versions-maven-plugin.version>
 		<maven-gpg-plugin.version>1.6</maven-gpg-plugin.version>
 		<maven-source-plugin.version>3.4.0</maven-source-plugin.version>
 		<maven-javadoc-plugin.version>3.12.0</maven-javadoc-plugin.version>