build(deps): bump kotlin from 2.3.20 to 2.3.21

Bumps `kotlin` from 2.3.20 to 2.3.21.

Updates `org.jetbrains.kotlin.multiplatform` from 2.3.20 to 2.3.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v2.3.20...v2.3.21)

Updates `org.jetbrains.kotlin.native.cocoapods` from 2.3.20 to 2.3.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v2.3.20...v2.3.21)

Updates `org.jetbrains.kotlin.plugin.compose` from 2.3.20 to 2.3.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v2.3.20...v2.3.21)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin.multiplatform
  dependency-version: 2.3.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin.native.cocoapods
  dependency-version: 2.3.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin.plugin.compose
  dependency-version: 2.3.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 
 androidcontextprovider = "1.0.1"
 filekit = "0.14.0"
-kotlin = "2.3.20"
+kotlin = "2.3.21"
 agp = "8.13.2"
 kotlinx-coroutines = "1.10.2"
 kotlinxBrowserWasmJs = "0.5.0"