Update plugin spotless to v7 (#370)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

gradle/libs.versions.toml

@@ -7,7 +7,7 @@ coroutines-test = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-test", ve
 
 [plugins]
 kotlin = { id = "org.jetbrains.kotlin.multiplatform", version = "2.1.0" }
-spotless = { id = "com.diffplug.spotless", version = "6.25.0" }
+spotless = { id = "com.diffplug.spotless", version = "7.0.0" }
 publish = { id = "com.vanniktech.maven.publish", version = "0.30.0" }
 dokka = { id = "org.jetbrains.dokka", version = "2.0.0" }
 kotlinApiDump = { id = "org.jetbrains.kotlinx.binary-compatibility-validator", version = "0.17.0" }