Bump com.diffplug.spotless from 6.3.0 to 6.4.2

Bumps com.diffplug.spotless from 6.3.0 to 6.4.2.

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

Signed-off-by: dependabot[bot] <support@github.com>

build.gradle.kts

@@ -2,7 +2,7 @@ import com.github.benmanes.gradle.versions.updates.DependencyUpdatesTask
 
 plugins {
     kotlin("jvm") version "1.6.20"
-    id("com.diffplug.spotless") version "6.3.0"
+    id("com.diffplug.spotless") version "6.4.2"
     id("io.gitlab.arturbosch.detekt") version "1.19.0"
     id("com.github.ben-manes.versions") version "0.42.0"
     id("org.jetbrains.dokka") version "1.6.10"