Remove java-operator-plugins

## Bug Report

https://github.com/operator-framework/java-operator-plugins is now deprecated and will probably be archived. The provided Quarkus plugin is now replaced with https://github.com/quarkiverse/quarkus-operator-sdk?tab=readme-ov-file#bootstrapping-a-project. We can now remove this integration from the operator-sdk.

I will work on this.
