🧹 Refactor test_graphics_canvas_drawing to improve maintainability

[Tcode-Motion]

🎯 What: The overly long test function test_graphics_canvas_drawing (110 lines) was split into two separate, concise test functions: test_graphics_canvas_drawing (for shape drawing) and test_graphics_canvas_save_png (for testing file capability requirements and saving).

💡 Why: This refactoring improves the readability and maintainability of the standard library tests by adhering to length guidelines and ensuring each test function focuses on a single logical behavior.

✅ Verification: Verified by visually reading the modified source code to confirm the correct split. Also ran cargo fmt --all and successfully executed the full workspace test suite (cargo test --workspace) ensuring all existing and newly created tests pass.

✨ Result: The test codebase is cleaner, easier to follow, and free of overly large, monolithic functions without breaking any existing test assertions.

---

PR created automatically by Jules for task 11273742184987321424 started by @Tcode-Motion

[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.