Merge pull request #72 from rabbitmq/dependabot/maven/com.diffplug.spotless-spotless-maven-plugin-2.21.0

Bump spotless-maven-plugin from 2.20.2 to 2.21.0

Author: acogoluegnes

pom.xml

@@ -89,7 +89,7 @@
     <buildnumber.plugin.version>1.4</buildnumber.plugin.version>
     <jruby.version>9.3.3.0</jruby.version>
     <jmh.version>1.34</jmh.version>
-    <spotless.version>2.20.2</spotless.version>
+    <spotless.version>2.21.0</spotless.version>
     <jacoco.version>0.8.7</jacoco.version>
     <!-- to sign artifacts when releasing -->
     <gpg.keyname>6026DFCA</gpg.keyname>