build(deps): bump multiplatform from 2.0.0-RC3 to 2.1.0-Beta1

Bumps multiplatform from 2.0.0-RC3 to 2.1.0-Beta1.

---
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

@@ -20,7 +20,7 @@ import org.jetbrains.kotlin.gradle.targets.js.yarn.YarnPlugin
 import org.jetbrains.kotlin.gradle.targets.js.yarn.YarnRootExtension
 
 plugins {
-    kotlin("multiplatform") version "2.0.0-RC3" apply false
+    kotlin("multiplatform") version "2.1.0-Beta1" apply false
     kotlin("plugin.serialization") version "2.0.0-RC3" apply false
     alias(libs.plugins.testlogger) apply false
     alias(libs.plugins.kotlinx.benchmark) apply false