refactor: remove unnecessary Arc<Mutex> from tool execution pipeline (#7979)

Signed-off-by: rabi <ramishra@redhat.com>
Co-authored-by: jh-block <jhugo@block.xyz>

crates/goose/src/conversation/message.rs

@@ -774,7 +774,6 @@ impl Message {
         }))
     }
 
-    /// Add a tool response to the message
     pub fn with_tool_response<S: Into<String>>(
         self,
         id: S,
@@ -783,15 +782,16 @@ impl Message {
         self.with_content(MessageContent::tool_response(id, result))
     }
 
-    pub fn with_tool_response_with_metadata<S: Into<String>>(
-        self,
+    pub fn add_tool_response_with_metadata<S: Into<String>>(
+        &mut self,
         id: S,
         result: ToolResult<CallToolResult>,
         metadata: Option<&ProviderMetadata>,
-    ) -> Self {
-        self.with_content(MessageContent::tool_response_with_metadata(
-            id, result, metadata,
-        ))
+    ) {
+        self.content
+            .push(MessageContent::tool_response_with_metadata(
+                id, result, metadata,
+            ));
     }
 
     /// Add an action required message for tool confirmation