chore(deps) update spotless, gradle for java 25 compat

Author: cgoetz-inovex

build.gradle

@@ -5,7 +5,7 @@ plugins {
 	id 'eclipse'
 	id 'pmd'
 
-	id 'com.diffplug.spotless' version '6.21.0'
+	id 'com.diffplug.spotless' version '8.1.0'
 
 	/* We have to use this 3rd party plugin for publishing to MavenCentral because as of AUG-2025 there is no official
 	 * plugin which supports publishing to MavenCentral Portal. */

gradle/wrapper/gradle-wrapper.jar

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.3.0-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME