refactor: eliminate the deprecation warning

[yingmanwumen]

chrono has deprecated some methods of NaiveDataTime: https://docs.rs/chrono/latest/chrono/naive/struct.NaiveDateTime.html#method.from_timestamp I apply cargo clippy to correct it, and all tests are passed locally.

What problem does this PR solve?

There're some compiling warnings related to some deprecated methods in chrono::NaiveDataTime.

What is changed and how it works?

Use the recommanded equal methods to replace the old ones.

Code changes

• Has Rust code change
• Has CI related scripts change

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

I ran cargo test locally in my machine and all of the testcases passed:

test result: ok. 99 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.60s

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Note for reviewer

It's a tiny refactor that doesn't alter the behavior of other codes.

[KKould]

In fact, I originally wanted to classify this issue into #182 because it needs to support time zones.
BTW, LGTM

[KKould]

Thanks for your contribution.🚀