Enable arti-client when it upgrades its dependency x25519-dalek

[upbqdn]

Motivation

Zebra's dependency arti-client v0.0.2 depends on x25519-dalek v2, which depends on an old version of zeroize that conflicts with other crates' dependencies. For this reason, we've temporarily disabled arti-client in #5481.

Solution

Enable and upgrade arti-client when it uses a new version of x25519-dalek, which doesn't depend on an old version of zeroize.

[mpguerra]

I think we can do this one soon

[oxarbitrage]

I am closing this in favor of #5492 because the issue with dalek is fixed in arti since a while. But there are other issues as described in #8328 (comment)