Remove outdated arrayvec dependency used by inferno

[teor2345]

Motivation

Zebra currently depends on 3 different versions of the arrayvec crate.
Some of these versions are more than 2 years old.

If we remove outdated dependencies, Zebra will compile faster, its binaries will be smaller, and it will be more secure.

Tasks

0. Check that the conflict still exists by removing the inferno exception from deny.toml, then running cargo deny check bans.

inferno Alternatives

Make flamegraph support an optional feature:

1. Make inferno an optional dependency of zebrad, and use a feature to activate flamegraph support

Upgrade versions:

1. Fork inferno and num-format, upgrade them to use the latest arrayvec, and make Zebra depend on our forked versions
2. Submit PRs upstream
3. Remove the exceptions for these crates in deny.toml.

[teor2345]

Closed by PRs #3011 and #3013.

[teor2345]

This wasn't actually resolved by these PRs.

[teor2345]

We should do the simplest fix as part of a future version upgrade.