fix: replace busy-wait loop with ontimer-driven ticks in Snake game

[kumudasrip]

📝 Description

This PR fixes the pause busy-wait issue in the Snake game. The game loop now uses event-driven ticks (screen.ontimer()) instead of a busy-wait loop, eliminating high CPU usage when paused.

🔗 Linked Issue

Closes #828

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📋 Contribution Checklist

• My code strictly adheres to the project guidelines (Standard library only, procedural code, clean spacing).
• I have verified that my files are placed in the correct directory.
• I have tested my changes thoroughly on my local machine.
• I have included interactive emojis and clean console/UI outputs.
• GSSoC 2026: I have been formally assigned to this issue and noted it above.

[vercel]

@kumudasrip is attempting to deploy a commit to the Anuj's projects Team on Vercel.

A member of the Team first needs to authorize it.

[kumudasrip]

Hi @steam-bell-92 , I have fixed the busy wait loop with ontimer driven ticks in the snake game and since all the checks have been passed, could you please review the PR whenever possible? Thank you!

[github-actions]

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