The plugin is broken with Kotlin 2.1.0

* What went wrong:
A problem occurred configuring project ':demo'.
> Could not create task ':demo:viteBuild'.
   > 'org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootExtension org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootPlugin$Companion.getKotlinNodeJsExtension(org.gradle.api.Project)'

Reported upstream: https://kotlinlang.slack.com/archives/C0B8L3U69/p1736281644920429

Fix tracking:

• Kotlin 2.1.20 release
• Conventions repo updated: OpenSavvy Conventions 1.6.3
• Gradle Playground updated: opensavvy/playgrounds/gradle!102 (merged)
• Vite plugin updated: !96 (merged)