Bump multiplatform from 1.8.22 to 1.9.0 in /whiskers-ktor-no-db

Bumps [multiplatform](https://github.com/JetBrains/kotlin) from 1.8.22 to 1.9.0.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/commits)

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

Signed-off-by: dependabot[bot] <[email protected]>

whiskers-ktor-no-db/build.gradle.kts

@@ -1,6 +1,6 @@
 plugins {
     application
-    kotlin("multiplatform") version "1.8.22"
+    kotlin("multiplatform") version "1.9.0"
     kotlin("plugin.serialization") version "1.8.22"
 }