chore(deps): update plugin com.diffplug.spotless to v8.4.0 (#1062)

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

Author: renovate[bot]

settings.gradle.kts

@@ -1,6 +1,6 @@
 pluginManagement {
     plugins {
-        id("com.diffplug.spotless") version "8.3.0"
+        id("com.diffplug.spotless") version "8.4.0"
         id("com.gradleup.shadow") version "9.4.0"
         id("com.google.protobuf") version "0.9.6"
         id("org.gradle.toolchains.foojay-resolver-convention") version "1.0.0"