Update plugin spotless to v8.1.0

Author: renovate[bot]

gradle/libs.versions.toml

@@ -110,4 +110,4 @@ kotlin = { id = "org.jetbrains.kotlin.jvm", version = "2.2.21" }
 nullaway = { id = "net.ltgt.nullaway", version = "2.3.0" }
 plantuml = { id = "io.freefair.plantuml", version = "9.1.0" }
 shadow = { id = "com.gradleup.shadow", version = "9.2.2" }
-spotless = { id = "com.diffplug.spotless", version = "8.0.0" }
+spotless = { id = "com.diffplug.spotless", version = "8.1.0" }