Tool call streams stay pending across any interrupt

Patch Changes

• #11087 534b43a Thanks @christian-bromann! - fix(langchain): keep tool call streams pending across any tool interrupt

  A raw interrupt() raised from inside a tool surfaced as a tool-error and rejected the call's un-awaited output promise, producing an unhandled rejection that crashed HITL runs. The tool-call stream transformer now treats any serialized graph interrupt as control flow (the call stays pending and resumes), not just humanInTheLoopMiddleware interrupts.