Bump org.jetbrains.kotlin.multiplatform from 1.7.20 to 1.7.21

Bumps [org.jetbrains.kotlin.multiplatform](https://github.com/JetBrains/kotlin) from 1.7.20 to 1.7.21.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/v1.7.21/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.7.20...v1.7.21)

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

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

build.gradle.kts

@@ -1,7 +1,7 @@
 plugins {
     `maven-publish`
     id("com.android.library") version "7.3.1" apply false
-    id("org.jetbrains.kotlin.multiplatform") version "1.7.20" apply false
+    id("org.jetbrains.kotlin.multiplatform") version "1.7.21" apply false
     id("org.jetbrains.kotlin.android") version "1.7.21" apply false
     id("org.jetbrains.compose") version "1.2.1" apply false
 }