Previously, we would specify the version and path of our workspace dependencies in each of our crates. This is error prone as https://github.com/libp2p/rust-libp2p/pull/3658#discussion_r1153278072 for example shows. Problems like these happened in the past too.
There is no need for us to ever depend on a earlier version than the most current one in our crates. It thus makes sense that we manage this version in a single place.
Cargo supports a feature called "workspace inheritance" which allows us to share a dependency declaration across a workspace and inherit it with `{ workspace = true }`.
We do this for all our workspace dependencies and for the MSRV.
Resolves#3787.
Pull-Request: #3715.
Instead of relying on `protoc` and buildscripts, we generate the bindings using `pb-rs` and version them within our codebase. This makes for a better IDE integration, a faster build and an easier use of `rust-libp2p` because we don't force the `protoc` dependency onto them.
Resolves#3024.
Pull-Request: #3312.
