Update plugin com.diffplug.spotless to v6.0.4 (#44) [skip ci]

Co-authored-by: Renovate Bot <[email protected]>

Author: renovate[bot]

build.gradle.kts

@@ -7,7 +7,7 @@ import java.net.URL
 
 plugins {
   kotlin("multiplatform") version "1.6.0"
-  id("com.diffplug.spotless") version "6.0.2"
+  id("com.diffplug.spotless") version "6.0.4"
   id("maven-publish")
   id("com.vanniktech.maven.publish") version "0.18.0"
   id("org.jetbrains.kotlinx.binary-compatibility-validator") version "0.8.0"