Update dependency com.diffplug.spotless:spotless-maven-plugin to v3.8.0

Author: renovate[bot]

pom.xml

@@ -148,7 +148,7 @@
       <plugin>
         <groupId>com.diffplug.spotless</groupId>
         <artifactId>spotless-maven-plugin</artifactId>
-        <version>3.2.1</version>
+        <version>3.8.0</version>
         <configuration>
           <java>
             <googleJavaFormat>