deps: update kotest to v6.0.3

Author: renovate[bot]

gradle/libs.versions.toml

@@ -38,7 +38,7 @@ jruby = "9.4.14.0"
 jslt = "0.1.14"
 jsonSchemaValidator = "1.5.8"
 kaml = "0.94.0"
-kotest = "6.0.2"
+kotest = "6.0.3"
 kotlinPoet = "2.2.0"
 kotlinxCoroutines = "1.10.2"
 kotlinxHtml = "0.12.0"