Bump org.jetbrains.kotlin.android in /06_recyclerview/diffutils

Bumps [org.jetbrains.kotlin.android](https://github.com/JetBrains/kotlin) from 2.2.20 to 2.2.21.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/v2.2.21/ChangeLog.md)
- [Commits](JetBrains/kotlin@v2.2.20...v2.2.21)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin.android
  dependency-version: 2.2.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

06_recyclerview/diffutils/gradle/libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 agp = "8.13.0"
-kotlin = "2.2.20"
+kotlin = "2.2.21"
 coreKtx = "1.17.0"
 junit = "4.13.2"
 junitVersion = "1.3.0"