fix: lazy load openai (#1294)

.changeset/afraid-pots-raise.md

examples/agent/large_toolcall_with_gpt4o.ts

packages/llamaindex/src/Settings.ts

packages/llamaindex/src/embeddings/fireworks.ts

packages/llamaindex/src/embeddings/together.ts

packages/llamaindex/src/index.edge.ts

packages/llamaindex/src/llm/deepinfra.ts

packages/llamaindex/src/llm/deepseek.ts

packages/llamaindex/src/llm/fireworks.ts

packages/llamaindex/src/llm/together.ts

packages/llamaindex/tests/init.test.ts

packages/llm/groq/src/llm.ts

packages/llm/openai/src/azure.ts

packages/llm/openai/src/embedding.ts

packages/llm/openai/src/index.ts

packages/llm/openai/src/llm.ts