Make GitRepository::status async and remove cx parameter (#27514)

This lays the groundwork for using `status` as part of the new agent
panel.

Release Notes:

- N/A

crates/extension_cli/src/main.rs

@@ -34,7 +34,7 @@ async fn main() -> Result<()> {
     env_logger::init();
 
     let args = Args::parse();
-    let fs = Arc::new(RealFs::default());
+    let fs = Arc::new(RealFs::new(None, gpui::background_executor()));
     let engine = wasmtime::Engine::default();
     let mut wasm_store = WasmStore::new(&engine)?;