Bump multiplatform from 2.0.21 to 2.1.0

Bumps [multiplatform](https://github.com/JetBrains/kotlin) from 2.0.21 to 2.1.0.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/v2.1.0/ChangeLog.md)
- [Commits](JetBrains/kotlin@v2.0.21...v2.1.0)

---
updated-dependencies:
- dependency-name: multiplatform
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

build.gradle.kts

@@ -1,5 +1,5 @@
 plugins {
-    kotlin("multiplatform") version "2.0.21"
+    kotlin("multiplatform") version "2.1.0"
     kotlin("plugin.serialization") version "2.0.21"
     id("org.jetbrains.kotlin.native.cocoapods") version "2.0.21"
     id("org.jetbrains.dokka") version "1.9.20"