Support for Gradle Configuration Cache

[jmfayard]

Hello Paul

I tried enabling Gradle's Configuration Cache with org.gradle.unsafe.configuration-cache=true in gradle.properties

But my task using Gradle Execfork Plugin doesn't suport it

5 problems were found storing the configuration cache.
- Gradle runtime: cannot serialize Gradle script object references as these are not supported with the configuration cache.
  See https://docs.gradle.org/7.4/userguide/configuration_cache.html#config_cache:requirements:disallowed_types
- Plugin 'com.github.psxpaul.execfork': registration of listener on 'Gradle.addBuildListener' is unsupported
  See https://docs.gradle.org/7.4/userguide/configuration_cache.html#config_cache:requirements:build_listeners
- Task `:checkExternalTools` of type `org.gradle.api.DefaultTask`: cannot serialize Gradle script object references as these are not supported with the configuration cache.
  See https://docs.gradle.org/7.4/userguide/configuration_cache.html#config_cache:requirements:disallowed_types
- Task `:runDatabase` of type `com.github.psxpaul.task.ExecFork`: cannot serialize object of type 'com.github.psxpaul.task.ExecJoin', a subtype of 'org.gradle.api.Task', as these are not supported with the configuration cache.
  See https://docs.gradle.org/7.4/userguide/configuration_cache.html#config_cache:requirements:task_access
- Task `:runDatabase` of type `com.github.psxpaul.task.ExecFork`: invocation of 'Task.project' at execution time is unsupported.
  See https://docs.gradle.org/7.4/userguide/configuration_cache.html#config_cache:requirements:use_project_during_execution

See https://docs.gradle.org/current/userguide/configuration_cache.html