Update plugin com.diffplug.spotless to v6.19.0

Author: renovate[bot]

build.gradle.kts

@@ -1,6 +1,6 @@
 plugins {
     id("com.diffplug.eclipse.apt") version "3.42.2" apply false
-    id("com.diffplug.spotless") version "6.13.0" apply false
+    id("com.diffplug.spotless") version "6.19.0" apply false
     id("org.domaframework.doma.compile") version "2.0.0" apply false
     kotlin("jvm") version "1.9.0" apply false
     kotlin("kapt") version "1.9.0" apply false