Replace rpc with proto dependency for the headless server crate (#19048)

Release Notes:

- N/A

Cargo.lock

@@ -5298,7 +5298,7 @@ dependencies = [
  "node_runtime",
  "postage",
  "project",
- "rpc",
+ "proto",
  "settings",
  "shellexpand 2.1.2",
  "signal-hook",

crates/headless/Cargo.toml

@@ -19,11 +19,11 @@ extension.workspace = true
 signal-hook.workspace = true
 gpui.workspace = true
 log.workspace = true
-rpc.workspace = true
 util.workspace = true
 node_runtime.workspace = true
 language.workspace = true
 project.workspace = true
+proto.workspace = true
 fs.workspace = true
 futures.workspace = true
 settings.workspace = true
@@ -34,5 +34,4 @@ postage.workspace = true
 client = { workspace = true, features = ["test-support"] }
 fs = { workspace = true, features = ["test-support"] }
 gpui = { workspace = true, features = ["test-support"] }
-rpc = { workspace = true, features = ["test-support"] }
 util = { workspace = true, features = ["test-support"] }

crates/headless/src/headless.rs

@@ -9,7 +9,7 @@ use language::LanguageRegistry;
 use node_runtime::NodeRuntime;
 use postage::stream::Stream;
 use project::Project;
-use rpc::{proto, ErrorCode, TypedEnvelope};
+use proto::{self, ErrorCode, TypedEnvelope};
 use settings::{Settings, SettingsStore};
 use std::path::Path;
 use std::{collections::HashMap, sync::Arc};