Add a crate for spawning tokio tasks in Zed (#23857)

Part of https://github.com/zed-industries/zed/pull/21092

As we're already depending on and using `tokio` to run `reqwest`, I've
added a crate to make running tokio futures more convenient. This should
unblock the Bedrock Cloud Model provider PR.

Note that since the `gpui_tokio` code is nearly trivial glue and I
expect that it will be useful for the nascent GPUI ecosystem, I've
elected to license it under Apache 2, like GPUI itself, instead of our
normal GPL license for Zed code.

Release Notes:

- N/A

crates/remote_server/Cargo.toml

@@ -36,6 +36,7 @@ futures.workspace = true
 git.workspace = true
 git_hosting_providers.workspace = true
 gpui.workspace = true
+gpui_tokio.workspace = true
 http_client.workspace = true
 language.workspace = true
 language_extension.workspace = true

crates/remote_server/src/unix.rs

@@ -9,6 +9,7 @@ use futures::channel::mpsc;
 use futures::{select, select_biased, AsyncRead, AsyncWrite, AsyncWriteExt, FutureExt, SinkExt};
 use git::GitHostingProviderRegistry;
 use gpui::{App, AppContext as _, Context, Entity, SemanticVersion, UpdateGlobal as _};
+use gpui_tokio::Tokio;
 use http_client::{read_proxy_from_env, Uri};
 use language::LanguageRegistry;
 use node_runtime::{NodeBinaryOptions, NodeRuntime};
@@ -425,6 +426,7 @@ pub fn execute_run(
         settings::init(cx);
         let app_version = AppVersion::init(env!("ZED_PKG_VERSION"));
         release_channel::init(app_version, cx);
+        gpui_tokio::init(cx);
 
         HeadlessProject::init(cx);
 
@@ -445,18 +447,21 @@ pub fn execute_run(
 
             let proxy_url = read_proxy_settings(cx);
 
-            let http_client = Arc::new(
-                ReqwestClient::proxy_and_user_agent(
-                    proxy_url,
-                    &format!(
-                        "Zed-Server/{} ({}; {})",
-                        env!("CARGO_PKG_VERSION"),
-                        std::env::consts::OS,
-                        std::env::consts::ARCH
-                    ),
+            let http_client = {
+                let _guard = Tokio::handle(cx).enter();
+                Arc::new(
+                    ReqwestClient::proxy_and_user_agent(
+                        proxy_url,
+                        &format!(
+                            "Zed-Server/{} ({}; {})",
+                            env!("CARGO_PKG_VERSION"),
+                            std::env::consts::OS,
+                            std::env::consts::ARCH
+                        ),
+                    )
+                    .expect("Could not start HTTP client"),
                 )
-                .expect("Could not start HTTP client"),
-            );
+            };
 
             let node_runtime = NodeRuntime::new(http_client.clone(), node_settings_rx);