Bump kotlin-stdlib from 1.5.31 to 1.6.21

Bumps [kotlin-stdlib](https://github.com/JetBrains/kotlin) from 1.5.31 to 1.6.21.
- [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: org.jetbrains.kotlin:kotlin-stdlib
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

cerberus-core/build.gradle

@@ -43,6 +43,6 @@ dependencies {
 configurations.all {
   resolutionStrategy {
     force "org.jetbrains.kotlin:kotlin-stdlib-common:1.6.21"
-    force "org.jetbrains.kotlin:kotlin-stdlib:1.5.31"
+    force "org.jetbrains.kotlin:kotlin-stdlib:1.6.21"
   }
 }