Consider using `[workspace.dependencies]` for shared dependencies

[steph-rs]

Currently each workspace member specifies dependency versions independently.
There are 10+ shared dependencies across crates that could be deduplicated.

Using [workspace.dependencies] in the root Cargo.toml would keep versions in sync and make upgrades easier.

Happy to open a PR if this is welcome

[ameba23]

Great catch. I agree it would be a good move to use shared dependencies.

But actually, things need a cross-repo refactor:

• attested-tls crate is being replaced with attested-tls from the attested-tls repo: https://github.com/flashbots/attested-tls in Switch proxy to use nested attested TLS protocol #152
• attestation-provider-server should really also move to that repo. Because the idea is that one is for things related to attestation and TLS, and this repo is only for the proxy part. So i would welcome a PRs to add that crate there and remove it from here.

So in the end this repo will have just one crate.

cc: @0x416e746f6e

[steph-rs]

Made these two PRs without any changes - only moving attestation-provider-server crate