Is is impossible to use CoroutinesTimeoutExtension with Java 8

[osipxd]

Describe the bug

CoroutinesTimeoutExtension uses some "new" APIs:

• Optional.or { ... } function which was added in Java 9
• Optional.isEmpty() function which was added in Java 11

So effectively the minimal supported JVM version is 11, which is specified in jdk_toolchain_version, while jvmTarget is set to JvmTarget.JVM_1_8.

Provide a Reproducer

1. Set the project JVM toolchain to 8

   kotlin {
       jvmToolchain(8)
   }

2. Add @CoroutinesTimeout to any test
3. Compile