Add #[must_use] to FileTimes::set_accessed and set_modified

[yashhzd]

Summary

FileTimes::set_accessed and FileTimes::set_modified take self by value and return Self (builder pattern). Without #[must_use], calling ft.set_modified(time) without using the return value silently does nothing, which is a common source of bugs.

This PR adds #[must_use] to both methods so that the compiler warns when the return value is discarded.

Example of the bug this prevents:

let ft = FileTimes::new();
ft.set_modified(modified); // silently does nothing - no warning!

With this change, the compiler will emit a warning for the above code, guiding users to use the builder pattern correctly:

let ft = FileTimes::new().set_modified(modified); // correct usage

Fixes #152231

[rustbot]

r? @Mark-Simulacrum

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[rustbot]

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  • 4e73ef4

[chenyukang]

there is already a PR for it: #152232

[chenyukang]

Hi. It looks like you used an LLM without reviewing its output sufficiently. At that point we become the reviewer of the LLM output, with you relaying our reviews back to the LLM as a proxy. That is a lot of work without a clear benefit, while being also frustrating for reviewers.

I am thus closing and locking this PR.

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