Update kotlinx.serialization to v1.8.1 (#2236)

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

gradle/libs.versions.toml

@@ -22,7 +22,7 @@ compose-destinations = "2.1.0"
 kotlin = "2.1.20"
 kotlinx-coroutines = "1.10.1"
 kotlinx-datetime = "0.6.2"
-kotlinx-serialization = "1.8.0"
+kotlinx-serialization = "1.8.1"
 ksp = "2.1.20-1.0.32"
 ktor = "3.1.2"
 okhttp = "5.0.0-alpha.14"