Remove netcat dependency (#28920)

Closes #28813
Closes #27749

Release Notes:

- Removed the need to have openbsd `netcat` (`nc`) installed on your
system in order to enter passwords for `git` or `ssh` (remote
development). If you previously installed `netcat` specifically for Zed,
you may uninstall it.

crates/remote_server/Cargo.toml

@@ -23,6 +23,7 @@ test-support = ["fs/test-support"]
 
 [dependencies]
 anyhow.workspace = true
+askpass.workspace = true
 async-watch.workspace = true
 backtrace = "0.3"
 chrono.workspace = true