Bump org.jetbrains.kotlinx:kotlinx-serialization-json (#127)

Bumps [org.jetbrains.kotlinx:kotlinx-serialization-json](https://github.com/Kotlin/kotlinx.serialization) from 1.7.3 to 1.8.1.
- [Release notes](https://github.com/Kotlin/kotlinx.serialization/releases)
- [Changelog](https://github.com/Kotlin/kotlinx.serialization/blob/master/CHANGELOG.md)
- [Commits](https://github.com/Kotlin/kotlinx.serialization/compare/v1.7.3...v1.8.1)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlinx:kotlinx-serialization-json
  dependency-version: 1.8.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

gradle/libs.versions.toml

@@ -4,7 +4,7 @@ kotlin = "2.1.20"
 dokka = "2.0.0"
 
 # libraries version
-serialization = "1.7.3"
+serialization = "1.8.1"
 coroutines = "1.10.2"
 ktor = "3.1.2"
 mockk = "1.13.13"