HTMLSemanticPreservingSplitter reorders inline text around tags (e.g. <strong>, <a>, etc.)

### 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 This bug is the result of the changes made in PR [#34587](https://github.com/langchain-ai/langchain/pull/34587). ### Reproduction Steps / Example Code (Python) ```python from langchain_text_splitters import HTMLSemanticPreservingSplitter html_content = """ <h1>Section 1</h1> <p>This is some long text that <strong>should</strong> be split into multiple chunks due to the small chunk size.</p> """ splitter = HTMLSemanticPreservingSplitter( headers_to_split_on=[("h1", "Header 1")], max_chunk_size=50, chunk_overlap=5 ) documents = splitter.split_text(html_content) # This results in the following result, where the text in the <strong> tag is moved to the beginning of the first chunk: # [Document(metadata={'Header 1': 'Section 1'}, page_content='should This is some long text that be split into'), # Document(me…