build(deps): bump kotestAssertionsCore from 5.5.5 to 5.8.1 (#6736)

Last version depending on kotlin stdlib 1.8.x

Author: rlazo

gradle/libs.versions.toml

@@ -43,7 +43,7 @@ jacksonDatabind = "2.18.2"
 javalite = "3.25.5"
 jsonassert = "1.5.0"
 kotest = "5.9.0" # Do not use 5.9.1 because it reverts the fix for https://github.com/kotest/kotest/issues/3981
-kotestAssertionsCore = "5.5.5"
+kotestAssertionsCore = "5.8.1"
 kotlin = "1.8.22"
 ktorVersion = "2.3.2"
 legacySupportV4 = "1.0.0"