Update sync_tool.py

Author: twishabansal

packages/toolbox-core/src/toolbox_core/sync_tool.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import asyncio
+import types
 from asyncio import AbstractEventLoop
 from inspect import Signature
 from threading import Thread
@@ -85,7 +86,7 @@ def __annotations__(self) -> dict[str, Any]:  # type: ignore[override]
         # Standard Python object attributes like __doc__ are technically "writable".
         # But not defining a setter function makes this a read-only property.
         # Mypy flags this issue in the type checks.
-        return self.__async_tool.__annotations__.copy()
+        return types.MappingProxyType(self.__async_tool.__annotations__)
 
     def __call__(self, *args: Any, **kwargs: Any) -> str:
         """