langchain[patch]: set maxsplit when parse python function docstring (#14121)
Description
when the desc of arg in python docstring contains ":", the
`_parse_python_function_docstring` will raise **ValueError: too many
values to unpack (expected 2)**.
A sample desc would be:
"""
Args:
error_arg: this is an arg with an additional ":" symbol
"""
So, set `maxsplit` parameter to fix it.