Bump kotlinxSerialization from 1.6.3 to 1.9.0

Bumps `kotlinxSerialization` from 1.6.3 to 1.9.0.

Updates `org.jetbrains.kotlinx:kotlinx-serialization-core` from 1.6.3 to 1.9.0
- [Release notes](https://github.com/Kotlin/kotlinx.serialization/releases)
- [Changelog](https://github.com/Kotlin/kotlinx.serialization/blob/master/CHANGELOG.md)
- [Commits](Kotlin/kotlinx.serialization@v1.6.3...v1.9.0)

Updates `org.jetbrains.kotlinx:kotlinx-serialization-json` from 1.6.3 to 1.9.0
- [Release notes](https://github.com/Kotlin/kotlinx.serialization/releases)
- [Changelog](https://github.com/Kotlin/kotlinx.serialization/blob/master/CHANGELOG.md)
- [Commits](Kotlin/kotlinx.serialization@v1.6.3...v1.9.0)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlinx:kotlinx-serialization-core
  dependency-version: 1.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.jetbrains.kotlinx:kotlinx-serialization-json
  dependency-version: 1.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 # libraries
 intellijStructure = "3.307"
 intellijPluginRepositoryRestClient = "2.0.46"
-kotlinxSerialization = "1.6.3"
+kotlinxSerialization = "1.9.0"
 okhttp = "4.12.0"
 retrofit = "2.11.0"
 undertow = "2.3.18.Final"