Update kotlin monorepo to v2.1.20 (#771)

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

Author: renovate[bot]

gradle/libs.versions.toml

@@ -3,7 +3,7 @@ springBoot = "3.4.3"
 springDependency = "1.1.7"
 springOauth2AuthorizationServer = "1.4.2"
 openapiGenerator = "7.12.0"
-kotlin = "2.1.10"
+kotlin = "2.1.20"
 swaggerRequestValidator = "2.44.1"
 lazysodium = "5.1.4"
 jna = "5.17.0"