Bug: can't build the sample "ClassyTaxiAppKotlin" - getting error "Unknown Kotlin JVM target: 21"

[AndroidDeveloperLB]

As the title says. I tried to build it, and it failed with just this error. I tried upgrading AGP, but it didn't help. Tried to use latest canary version of Android Studio...

It says:

Execution failed for task ':app:kaptGenerateStubsDebugKotlin'.
> Error while evaluating property 'compilerOptions.jvmTarget' of task ':app:kaptGenerateStubsDebugKotlin'.
   > Failed to calculate the value of property 'jvmTarget'.
      > Unknown Kotlin JVM target: 21