Bump org.jetbrains.kotlin:kotlin-bom from 1.9.20 to 1.9.21

Bumps [org.jetbrains.kotlin:kotlin-bom](https://github.com/JetBrains/kotlin) from 1.9.20 to 1.9.21.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.9.20...v1.9.21)

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

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

app/build.gradle.kts

@@ -73,7 +73,7 @@ android {
 
 dependencies {
     // Kotlin
-    implementation(platform("org.jetbrains.kotlin:kotlin-bom:1.9.20"))
+    implementation(platform("org.jetbrains.kotlin:kotlin-bom:1.9.21"))
 
     // AndroidX
     implementation("androidx.activity:activity-compose:1.8.1")