airspec (internal): Prepare for Scala Native 0.5 support

[xerial]

To support Scala Native, airspec needs to support Scala Native as airspec is used for testing airframe modules.

• Target only for Scala 3 for reducing the maintenance overhead
• Compilation passed, but need to check why no test class is found

Challenges:

• No java.util.logging, which is necessary for airframe-log
• No java.util.concurrent.Executor