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

crates/remote_server/src/main.rs

@@ -8,6 +8,10 @@ use std::path::PathBuf;
 struct Cli {
     #[command(subcommand)]
     command: Option<Commands>,
+    /// Used for SSH/Git password authentication, to remove the need for netcat as a dependency,
+    /// by having Zed act like netcat communicating over a Unix socket.
+    #[arg(long, hide = true)]
+    askpass: Option<String>,
 }
 
 #[derive(Subcommand)]
@@ -46,6 +50,11 @@ fn main() {
 
     let cli = Cli::parse();
 
+    if let Some(socket_path) = &cli.askpass {
+        askpass::main(socket_path);
+        return;
+    }
+
     let result = match cli.command {
         Some(Commands::Run {
             log_file,