build(deps): bump ktVersion from 2.1.0 to 2.2.21 in /app

Bumps `ktVersion` from 2.1.0 to 2.2.21.

Updates `android` from 2.1.0 to 2.2.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v2.1.0...v2.2.21)

Updates `plugin.serialization` from 2.1.0 to 2.2.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v2.1.0...v2.2.21)

---
updated-dependencies:
- dependency-name: android
  dependency-version: 2.2.21
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: plugin.serialization
  dependency-version: 2.2.21
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

app/build.gradle.kts

@@ -6,7 +6,7 @@ import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 plugins {
     id("com.android.application") version "8.13.1"
 
-    val ktVersion = "2.1.0"
+    val ktVersion = "2.2.21"
 
     kotlin("android") version ktVersion
     kotlin("plugin.serialization") version ktVersion