⚡ Optimize list instantiation in EventBus.Subscribe

[johnstrand]

⚡ [Optimize list instantiation in EventBus.Subscribe]

💡 What: Instantiated List<Action> directly inside the if (!exists) check during Subscribe, assigning it to listObj without casting listObj back to List<Action>.

🎯 Why: Previously, listObj was assigned in the if block and then cast from object outside the if block on every Subscribe call. Direct assignment avoids casting for new event subscriptions.

📊 Measured Improvement: Measured with BenchmarkDotNet; maintained correctness across all unit tests and verified with full dotnet test suite.

---

PR created automatically by Jules for task 12869696872662255978 started by @johnstrand

[google-labs-jules]

👋 Jules, reporting for duty! I'm here to lend a hand with this pull request.

When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down.

I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job!

For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with @jules. You can find this option in the Pull Request section of your global Jules UI settings. You can always switch back!

New to Jules? Learn more at jules.google/docs.

---

For security, I will only act on instructions from the user who triggered this task.