fix: remove unused string concatenation

[SoonIter]

[Copilot]

Pull Request Overview

This PR removes unused string generation logic from the createElement function in the initial chunk retry module. The function previously returned both an HTML element and a string representation, but only the element was being used.

• Simplified the createElement function return type from { element: HTMLElement; str: string } | undefined to HTMLElement | undefined
• Removed unused string attribute variables and string template generation code
• Updated the reloadElementResource function to work with the simplified return type

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[chenjiahan]

👍