Update dependency org.jetbrains.dokka to v1.8.20

| datasource | package                                               | from   | to     |
| ---------- | ----------------------------------------------------- | ------ | ------ |
| maven      | org.jetbrains.dokka:org.jetbrains.dokka.gradle.plugin | 1.8.10 | 1.8.20 |

gradle/projects.libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 arrow = "1.1.5"
-dokka = "1.8.10"
+dokka = "1.8.20"
 arrowGradleConfig = "0.11.0"
 kotlin = "1.8.21"
 kotest = "5.6.2"