LangChain Core 1.7.0 changes streamed tool-call arguments

Raw tool-call arguments now arrive as tool-call-delta slices instead of block-delta snapshots. High-level .tool_calls.get() and .output remain unchanged. If your code consumes raw stream events, assemble the slices or pin below 1.7 until the consumer is updated. ⁵

Relevant to: LangChain applications that parse raw streamed tool-call events.