Bump com.diffplug.spotless:spotless-maven-plugin in /lang/java (#3575)

Bumps [com.diffplug.spotless:spotless-maven-plugin](https://github.com/diffplug/spotless) from 3.0.0 to 3.1.0.
- [Release notes](https://github.com/diffplug/spotless/releases)
- [Changelog](https://github.com/diffplug/spotless/blob/main/CHANGES.md)
- [Commits](diffplug/spotless@lib/3.0.0...lib/3.1.0)

---
updated-dependencies:
- dependency-name: com.diffplug.spotless:spotless-maven-plugin
  dependency-version: 3.1.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pom.xml

@@ -62,7 +62,7 @@
     <maven-source-plugin.version>3.3.1</maven-source-plugin.version>
     <maven-toolchains-plugin.version>3.2.0</maven-toolchains-plugin.version>
     <plugin-tools-javadoc.version>3.5.2</plugin-tools-javadoc.version>
-    <spotless-maven-plugin.version>3.0.0</spotless-maven-plugin.version>
+    <spotless-maven-plugin.version>3.1.0</spotless-maven-plugin.version>
     <maven-surefire-plugin.version>3.5.4</maven-surefire-plugin.version>
 
     <!-- Pin output timestamp to make the Java build reproducible -->