fix: allow concurrent tool execution within the same MCP extension (#7202)

Signed-off-by: rabi <ramishra@redhat.com>

crates/goose-cli/src/scenario_tests/scenario_runner.rs

@@ -142,7 +142,6 @@ where
     F: Fn(&ScenarioResult) -> Result<()>,
 {
     use goose::config::ExtensionConfig;
-    use tokio::sync::Mutex;
 
     goose::agents::moim::SKIP.with(|f| f.set(true));
 
@@ -229,7 +228,7 @@ where
                 bundled: None,
                 available_tools: vec![],
             },
-            Arc::new(Mutex::new(Box::new(mock_client))),
+            Arc::new(mock_client),
             None,
             None,
         )