Update plugin dokka to v2

Author: renovate[bot]

gradle/libs.versions.toml

@@ -11,7 +11,7 @@ ktfmt = "0.56"
 [plugins]
 kotlin-jvm = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
 binaryCompatibilityValidator = { id = "org.jetbrains.kotlinx.binary-compatibility-validator", version = "0.18.1" }
-dokka = { id = "org.jetbrains.dokka", version = "1.9.20" }
+dokka = { id = "org.jetbrains.dokka", version = "2.1.0" }
 ksp = { id = "com.google.devtools.ksp", version.ref = "ksp" }
 mavenPublish = { id = "com.vanniktech.maven.publish", version = "0.35.0" }
 spotless = { id = "com.diffplug.spotless", version = "8.2.1" }