[API]: Bump kotlinVersion from 1.9.24 to 2.0.21 in /noty-api

Bumps `kotlinVersion` from 1.9.24 to 2.0.21.

Updates `org.jetbrains.kotlin:kotlin-gradle-plugin` from 1.9.24 to 2.0.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.9.24...v2.0.21)

Updates `org.jetbrains.kotlin:kotlin-serialization` from 1.9.24 to 2.0.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.9.24...v2.0.21)

Updates `org.jetbrains.kotlin:kotlin-stdlib` from 1.9.24 to 2.0.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.9.24...v2.0.21)

Updates `org.jetbrains.kotlin:kotlin-reflect` from 1.9.24 to 2.0.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.9.24...v2.0.21)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin:kotlin-gradle-plugin
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: org.jetbrains.kotlin:kotlin-serialization
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: org.jetbrains.kotlin:kotlin-stdlib
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: org.jetbrains.kotlin:kotlin-reflect
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

noty-api/build.gradle

@@ -16,7 +16,7 @@
 
 buildscript {
     ext {
-        kotlinVersion = "1.9.24"
+        kotlinVersion = "2.0.21"
         kotlinSerializerVersion = "1.5.1"
         ktlintVersion = "11.6.1"
         coroutinesVersion = "1.8.1"