Update dependency io.kotest.multiplatform to v6

| datasource | package                                                       | from  | to          |
| ---------- | ------------------------------------------------------------- | ----- | ----------- |
| maven      | io.kotest.multiplatform:io.kotest.multiplatform.gradle.plugin | 5.9.1 | 6.0.0-LOCAL |

Author: renovate[bot]

libs.versions.toml

@@ -2,7 +2,7 @@
 arrow = "2.0.1"
 coroutines = "1.7.3"
 kotlin = "2.1.10"
-kotest = "5.9.1"
+kotest = "6.0.0-LOCAL"
 kover = "0.9.1"
 detekt = "1.23.7"
 ktor = "3.1.0"