Bump the major group with 4 updates

Bumps the major group with 4 updates: [org.jetbrains.kotlin:kotlin-stdlib](https://github.com/JetBrains/kotlin), [org.jetbrains.kotlin:kotlin-test-junit5](https://github.com/JetBrains/kotlin), [org.jetbrains.kotlin.jvm](https://github.com/JetBrains/kotlin) and [org.jetbrains.kotlin.plugin.serialization](https://github.com/JetBrains/kotlin).


Updates `org.jetbrains.kotlin:kotlin-stdlib` from 1.8.20 to 2.0.20
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.8.20...v2.0.20)

Updates `org.jetbrains.kotlin:kotlin-test-junit5` from 1.8.20 to 2.0.20
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.8.20...v2.0.20)

Updates `org.jetbrains.kotlin.jvm` from 1.8.20 to 2.0.20
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.8.20...v2.0.20)

Updates `org.jetbrains.kotlin.plugin.serialization` from 1.8.20 to 2.0.20
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.8.20...v2.0.20)

Updates `org.jetbrains.kotlin:kotlin-test-junit5` from 1.8.20 to 2.0.20
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.8.20...v2.0.20)

Updates `org.jetbrains.kotlin.jvm` from 1.8.20 to 2.0.20
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.8.20...v2.0.20)

Updates `org.jetbrains.kotlin.plugin.serialization` from 1.8.20 to 2.0.20
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.8.20...v2.0.20)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin:kotlin-stdlib
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: major
- dependency-name: org.jetbrains.kotlin:kotlin-test-junit5
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: major
- dependency-name: org.jetbrains.kotlin.jvm
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: major
- dependency-name: org.jetbrains.kotlin.plugin.serialization
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: major
- dependency-name: org.jetbrains.kotlin:kotlin-test-junit5
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: major
- dependency-name: org.jetbrains.kotlin.jvm
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: major
- dependency-name: org.jetbrains.kotlin.plugin.serialization
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: major
...

Signed-off-by: dependabot[bot] <support@github.com>

gradle/libs.versions.toml

@@ -7,7 +7,7 @@ hoplite = "2.7.0"
 jjwt = "0.12.5"
 java-stellar-sdk = "0.43.2"
 dokka = "1.6.10"
-kotlin = "1.8.20"
+kotlin = "2.0.20"
 kotlinx-json = "1.5.0"
 kotlinx-datetime = "0.4.0"
 ktor = "2.2.1"