text-splitters: SpacyTextSplitter ignores max_length with pipeline="sentencizer"

### Submission checklist - [x] This is a bug, not a usage question. - [x] I added a clear and descriptive title that summarizes this issue. - [x] I used the GitHub search to find a similar question and didn't find it. - [x] I am sure that this is a bug in LangChain rather than my code. - [x] The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package). - [x] This is not related to the langchain-community package. - [x] I posted a self-contained, minimal, reproducible example. A maintainer can copy it and run it AS IS. ### Package (Required) - [ ] langchain - [ ] langchain-openai - [ ] langchain-anthropic - [ ] langchain-classic - [ ] langchain-core - [ ] langchain-model-profiles - [ ] langchain-tests - [x] langchain-text-splitters - [ ] langchain-chroma - [ ] langchain-deepseek - [ ] langchain-exa - [ ] langchain-fireworks - [ ] langchain-groq - [ ] langchain-huggingface - [ ] langchain-mistralai - [ ] langchain-nomic - [ ] langchain-ollama - [ ] langchain-openrouter - [ ] langchain-perplexity - [ ] langchain-qdrant - [ ] langchain-xai - [ ] Other / not sure / general ### Related Issues / PRs _No response_ ### Reproduction Steps / Example Code (Python) ```python from types import SimpleNamespace from unittest.mock import Mock, patch from langchain_text_splitters import SpacyTextSplitter # Isolate LangChain's configuration forwarding; no spaCy/model install needed. nlp = Mock() nlp.max_length = 1_000_000 modules = { "spacy": SimpleNamespace(), "spacy.lang.en": SimpleNamespace(English=lambda: nlp), } with patch( "langchain_text_splitters.spacy.import_module", side_effect=modules.__getitem__, ): splitter = SpacyTextSplitter( pipeline="sentencizer", max_length=2_000_000 ) print(splitter._tokenizer.max_length) # Actual: 1000000 assert splitter._tokenizer.max_length == 2_000_000 ``` ### Error Message and Stack Trace (if applicable) ```shell 1000000 Traceback (most recent call last): …