chore(deps): update kotlin monorepo to v1.9.21 (#1165)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [org.jetbrains.kotlin.plugin.spring](https://kotlinlang.org/)
([source](https://github.com/JetBrains/kotlin)) | `1.9.20` -> `1.9.21`
|
[![age](https://developer.mend.io/api/mc/badges/age/maven/org.jetbrains.kotlin.plugin.spring/1.9.21?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
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|
[![passing](https://developer.mend.io/api/mc/badges/compatibility/maven/org.jetbrains.kotlin.plugin.spring/1.9.20/1.9.21?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
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|
| [org.jetbrains.kotlin.jvm](https://kotlinlang.org/)
([source](https://github.com/JetBrains/kotlin)) | `1.9.20` -> `1.9.21`
|
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|
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|
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|
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samples/sample-spring-boot-echo-kotlin/build.gradle.kts

@@ -17,8 +17,8 @@
 plugins {
     id("sdk.java-library")
     id("sdk.spring-boot")
-    kotlin("jvm") version "1.9.20"
-    kotlin("plugin.spring") version "1.9.20"
+    kotlin("jvm") version "1.9.21"
+    kotlin("plugin.spring") version "1.9.21"
 }
 
 dependencies {