getMetrics appears to be miscounting blank lines in docstrings

The definition of the python function `combine_docs` starts on line 227 in [combine_documents/map_reduce.py](https://github.com/langchain-ai/langchain/blob/master/libs/langchain/langchain_classic/chains/combine_documents/map_reduce.py) and ends on line 259.

[func-def.txt](https://github.com/user-attachments/files/23375865/func-def.txt)
Running the above QL script on the latest langchain database produces the values:

func.getMetrics().getNumberOfLines() = 33
func.getMetrics().getNumberOfLinesOfCode() = 27 # Should be 26
func.getMetrics().getNumberOfLinesOfComments() = 2
func.getMetrics().getNumberOfLinesOfDocStrings() = 5

I suspect that the number of blank line in the docstring might be a factor.
The above function contains one blank line in a docstring, while the example below contains two blank lines in a docstring.

The function `collapse_docs` starts on line 67 in [combine_documents/reduce.py](https://github.com/langchain-ai/langchain/blob/master/libs/langchain/langchain_classic/chains/combine_documents/reduce.py) and ends on line 96.

The above QL script produces the values:

func.getMetrics().getNumberOfLines() = 30
func.getMetrics().getNumberOfLinesOfCode() = 12 # Should be 14
func.getMetrics().getNumberOfLinesOfComments() = 0
func.getMetrics().getNumberOfLinesOfDocStrings() = 16

使用連結的 QL 指令碼和附件，重現 libs/langchain/langchain_classic/chains/combine_documents/map_reduce.py 中 combine_docs 以及 combine_documents/reduce.py 中 collapse_docs 的報告指標。將總數、程式碼、註解和 docstring 的計數與所述預期值進行比較，尤其關注 docstring 中的空白行。當兩個範例的指標都持續回報預期計數時，即表示完成。

由索引模型根據 Issue 內容生成。