Fix extension manager resource deadlock (#5066)

Signed-off-by: alexyao2015 <alexyao2015@users.noreply.github.com>
Co-authored-by: alexyao2019@gmail.com <alexyao2015@users.noreply.github.com>

crates/goose/src/agents/extension_manager.rs

@@ -705,9 +705,13 @@ impl ExtensionManager {
         // Loop through each extension and try to read the resource, don't raise an error if the resource is not found
         // TODO: do we want to find if a provided uri is in multiple extensions?
         // currently it will return the first match and skip any others
-        for extension_name in self.extensions.lock().await.keys() {
+
+        // Collect extension names first to avoid holding the lock during iteration
+        let extension_names: Vec<String> = self.extensions.lock().await.keys().cloned().collect();
+
+        for extension_name in extension_names {
             let result = self
-                .read_resource_from_extension(uri, extension_name, cancellation_token.clone())
+                .read_resource_from_extension(uri, &extension_name, cancellation_token.clone())
                 .await;
             match result {
                 Ok(result) => return Ok(result),