Update dependency org.jetbrains.kotlinx:kotlinx-serialization-json to v1.7.3

Author: renovate[bot]

Diff for: samples/ktor-all-platforms-app/gradle/libs.versions.toml

@@ -17,7 +17,7 @@ compose-plugin = "1.6.11"
 junit = "4.13.2"
 ktor = "2.3.12"
 logback = "1.5.8"
-kotlinx-serialization-json = "1.7.1"
+kotlinx-serialization-json = "1.7.3"
 kotlinx-coroutines-core = "1.9.0"
 kotlinx-rpc = "0.2.4"