Merge pull request #1351 from square/renovate/com.diffplug.spotless-s…

…potless-plugin-gradle-6.x

Update dependency com.diffplug.spotless:spotless-plugin-gradle to v6.21.0

gradle/libs.versions.toml

@@ -15,7 +15,7 @@ jmh-gradle-plugin = { module = "me.champeau.jmh:jmh-gradle-plugin", version = "0
 jmh-core = { module = "org.openjdk.jmh:jmh-core", version.ref = "jmh" }
 jmh-generator = { module = "org.openjdk.jmh:jmh-generator-annprocess", version.ref = "jmh" }
 dokka = { module = "org.jetbrains.dokka:dokka-gradle-plugin", version = "1.9.0" }
-spotless = { module = "com.diffplug.spotless:spotless-plugin-gradle", version = "6.20.0" }
+spotless = { module = "com.diffplug.spotless:spotless-plugin-gradle", version = "6.21.0" }
 bnd = { module = "biz.aQute.bnd:biz.aQute.bnd.gradle", version = "6.4.0" }
 vanniktech-publish-plugin = { module = "com.vanniktech:gradle-maven-publish-plugin", version = "0.25.3" }
 test-junit = { module = "junit:junit", version = "4.13.2" }