[LangChain-Core v1]Did the openai:convert_to-openai_data-block function miss the processing of video? And other providers' converters also do not handle videos

### Checked other resources - [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 read what a minimal reproducible example is (https://stackoverflow.com/help/minimal-reproducible-example). - [x] I posted a self-contained, minimal, reproducible example. A maintainer can copy it and run it AS IS. ### Example Code def convert_to_openai_data_block( block: dict, api: Literal["chat/completions", "responses"] = "chat/completions" ) -> dict: """Format standard data content block to format expected by OpenAI. "Standard data content block" can include old-style LangChain v0 blocks (URLContentBlock, Base64ContentBlock, IDContentBlock) or new ones. """ if block["type"] == "image": chat_completions_block = convert_to_openai_image_block(block) if api == "responses": formatted_block = { "type": "input_image", "image_url": chat_completions_block["image_url"]["url"], } if chat_completions_block["image_url"].get("detail"): formatted_block["detail"] = chat_completions_block["image_url"][ "detail" ] else: formatted_block = chat_completions_block elif block["type"] == "file": if block.get("source_type") == "base64" or "base64" in block: # Handle v0 format (Base64CB): {"source_type": "base64", "data": "...", ...} # Handle v1 format (IDCB): {"base64": "...", ...} base64_data = block["data"] if "source_type" in block else block["base64"] file = {"file_data": f"…