chore: switch from backoff to backon

[ramfox]

Description

backoff is no longer maintained, upgrade path in cargo-deny indicates switching to backon.

Notes & open questions

There are some options in backon for using sleepers in the retry that are Wasm compatible: https://docs.rs/backon/1.4.0/backon/#sleep

I'm curious if we should be taking advantage.

Further questions:
how do I resolve the paste cargo-deny issue?
I don't: added paste and humantime advisories to the "allow" list

Change checklist

• Self-review.

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Documentation for this PR has been generated and is available at: https://n0-computer.github.io/iroh/pr/3227/docs/iroh/

Last updated: 2025-03-13T17:43:25Z

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[matheus23]

Thanks for this. backon even has a better API than backoff IMO.

Also this makes me consider moving the retry logic into the iroh_relay::ClientBuilder.

[flub]

Goodness, why do we have these unmaintained advisories? Unmaintained crates are great! They don't update all the time. Why can't we have finished software?