Update plugin dokka to v1.9.0

Author: renovate[bot]

gradle/libs.versions.toml

@@ -22,7 +22,7 @@ picnic = "com.jakewharton.picnic:picnic:0.7.0"
 r8 = "com.android.tools:r8:8.1.56"
 
 [plugins]
-dokka = "org.jetbrains.dokka:1.8.20"
+dokka = "org.jetbrains.dokka:1.9.0"
 kotlin-jvm = "org.jetbrains.kotlin.jvm:1.9.10"
 mavenPublish = "com.vanniktech.maven.publish:0.25.3"
 spotless = "com.diffplug.spotless:6.21.0"