chore(deps): update dependency io.kotest:kotest-assertions-core to v6

Author: renovate[bot]

gradle/libs.versions.toml

@@ -10,7 +10,7 @@ junit = "5.10.2"
 ktoml = "0.5.1"
 multiplatform-diff = "0.5.0"
 kotlinpoet = "2.0.0"
-kotest = "5.8.1"
+kotest = "6.1.5"
 sarif4k = "0.5.0"
 sarif-utils = "0.2.2"
 log4j = "2.23.1"