Add Configuration Cache support status

Apply [`gradle-plugin-compatibility-plugin`](https://github.com/gradle/gradle-plugin-compatibility-plugin) and declare CC support status when publishing.

Ideally, this should be backed with CC-verifying e2e tests for the plugin.

Start by reviewing the plugin publishing setup and the gradle-plugin-compatibility-plugin documentation. Then identify the appropriate place for configuration-cache support status and the end-to-end test entry point. Done means the published plugin declares its CC status and the plugin has CC-verifying e2e coverage.

Written by the indexing model from the issue text.