feat(prebuilt): add support for handle_tool_errors with single exception type (#6021)

This PR extends the `ToolNode` `handle_tool_errors` property to also
accept a single exception type: `type[Exception]`.

Example:
```python
tool_node_with_error_handling = ToolNode(
    [tool1, tool2, tool3], handle_tool_errors=ValueError
).invoke(...)
"""A tool node that will only retry a failed tool call if a ValueError is raised"""
```

libs/prebuilt/tests/test_tool_node.py

@@ -274,10 +274,12 @@ async def test_tool_node_error_handling() -> None:
 
     # test catching all exceptions, via:
     # - handle_tool_errors = True
+    # - passing a single exception
     # - passing a tuple of all exceptions
     # - passing a callable with all exceptions in the signature
     for handle_tool_errors in (
         True,
+        Exception,
         (ValueError, ToolException, ToolInvocationError),
         handle_all,
     ):