Update kotlinx.serialization to v1.9.0 (#2443)

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

gradle/libs.versions.toml

@@ -21,7 +21,7 @@ compose-destinations = "2.2.0"
 kotlin = "2.2.0"
 kotlinx-coroutines = "1.10.2"
 kotlinx-datetime = "0.7.0"
-kotlinx-serialization = "1.8.1"
+kotlinx-serialization = "1.9.0"
 ksp = "2.2.0-2.0.2"
 ktor = "3.1.3"
 okhttp = "5.0.0-alpha.16"