Remove workspace-hack (#40216)

We've been considering removing workspace-hack for a couple reasons:
- Lukas ran into a situation where its build script seemed to be causing
spurious rebuilds. This seems more likely to be a cargo bug than an
issue with workspace-hack itself (given that it has an empty build
script), but we don't necessarily want to take the time to hunt that
down right now.
- Marshall mentioned hakari interacts poorly with automated crate
updates (in our case provided by rennovate) because you'd need to have
`cargo hakari generate && cargo hakari manage-deps` after their changes
and we prefer to not have actions that make commits.

Currently removing workspace-hack causes our workspace to grow from
~1700 to ~2000 crates being built (depending on platform), which is
mainly a problem when you're building the whole workspace or running
tests across the the normal and remote binaries (which is where
feature-unification nets us the most sharing). It doesn't impact
incremental times noticeably when you're just iterating on `-p zed`, and
we'll hopefully get these savings back in the future when
rust-lang/cargo#14774 (which re-implements the functionality of hakari)
is finished.

Release Notes:

- N/A

crates/remote/src/transport/ssh.rs

@@ -198,7 +198,7 @@ impl RemoteConnection for SshRemoteConnection {
                 output.status.success(),
                 "failed to upload directory {} -> {}: {}",
                 src_path.display(),
-                dest_path.to_string(),
+                dest_path,
                 String::from_utf8_lossy(&output.stderr)
             );
 

crates/remote/src/transport/wsl.rs

@@ -407,7 +407,7 @@ impl RemoteConnection for WslRemoteConnection {
                     anyhow!(
                         "failed to upload directory {} -> {}: {}",
                         src_path.display(),
-                        dest_path.to_string(),
+                        dest_path,
                         e
                     )
                 })?;