fix: multiple tool call (#905)

packages/core/e2e/node/openai.e2e.ts

packages/core/e2e/node/snapshot/agent.snap

packages/core/e2e/node/snapshot/agent_stream.snap

...re/e2e/node/snapshot/agent_with_object_function_call.snap

...s/core/e2e/node/snapshot/agent_with_object_retriever.snap

...core/e2e/node/snapshot/anthropic-agent-multiple-chat.snap

packages/core/e2e/node/snapshot/anthropic-agent.snap

packages/core/e2e/node/snapshot/gpt-4-turbo.snap

packages/core/e2e/node/snapshot/llm-anthropic.snap

...es/core/e2e/node/snapshot/openai_agent_system_prompt.snap

packages/core/e2e/node/snapshot/react-agent-stream.snap

packages/core/e2e/node/snapshot/react-agent.snap

packages/core/src/agent/anthropic.ts

packages/core/src/agent/openai.ts

packages/core/src/llm/anthropic.ts

packages/core/src/llm/openai.ts

packages/core/src/llm/types.ts