build(deps): bump org.jetbrains.kotlin.android from 2.0.0 to 2.0.21

Bumps [org.jetbrains.kotlin.android](https://github.com/JetBrains/kotlin) from 2.0.0 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@v2.0.0...v2.0.21)

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

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

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 #noinspection GradleDependency
 agp = "8.2.2" # 8.3.0 causes java verifier error: https://github.com/ReVanced/revanced-patches/issues/2818
 annotation = "1.8.0"
-kotlin = "2.0.0"
+kotlin = "2.0.21"
 appcompat = "1.7.0-rc01"
 okhttp = "5.0.0-alpha.14"
 retrofit = "2.11.0"