Improve success message for plugin registry release

- Enhanced success message to show "released to Nextflow Registry"
- Display full registry URI instead of just hostname for better clarity
- Message now reads: "🎉 SUCCESS\! Plugin 'name' version X.Y.Z has been successfully released to Nextflow Registry [https://registry.example.com/]\!"

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: pditommaso

src/main/groovy/io/nextflow/gradle/registry/RegistryReleaseTask.groovy

@@ -61,6 +61,6 @@ class RegistryReleaseTask extends DefaultTask {
         client.release(project.name, version, project.file(zipFile))
 
         // Celebrate successful plugin upload! 🎉
-        project.logger.lifecycle("🎉 SUCCESS! Plugin '${project.name}' version ${version} has been successfully uploaded to ${registryUri.host}!")
+        project.logger.lifecycle("🎉 SUCCESS! Plugin '${project.name}' version ${version} has been successfully released to Nextflow Registry [${registryUri}]!")
     }
 }