feat: update metrics package to support modern rust

[daeho-ro]

What does this PR do?

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you read the contributor guideline?
• Was this discussed/approved via a GitHub issue or the forum? Please add a link to it if that's the case.
• Did you make sure to update the documentation with your changes? Here are the documentation guidelines.
• Did you write any new necessary tests? If applicable, did you include or update the insta snapshots?

Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors who may be interested in your PR.

[alvarobartt]

Hey @daeho-ro, could you please elaborate on what do you mean by "support modern rust"? Since as per https://github.com/metrics-rs/metrics/blob/main/metrics/CHANGELOG.md#0230---2024-05-27 it seems that the MSRV is already 1.70+ and we don't leverage any of the newer features or patches in the more recent versions, so I don't see a strong reason to update from 0.23 to 0.23.1, but I might be wrong so feel free to elaborate further if there's a rationale 👍🏻

[daeho-ro]

metrics-rs/metrics#564

0.23 doesn't build with rust 1.94, so that is why I open a PR.

[alvarobartt]

Awesome @daeho-ro, thanks for the clarification! I'll merge to support Rust 1.94 as it's stable, though on Text Embeddings Inference we technically validate support on Rust 1.92 🤗