node-integration-tests: port AI and gen_ai suites to span streaming

Follow the porting recipe in the parent issue.

These suites assert on deep `gen_ai` attribute sets on child spans, so the `{ value, type }` attribute shape and the collect-across-envelopes rule matter more here than anywhere else.

## Suites

* `tracing/openai`, `tracing/openai/openai-tool-calls`, `tracing/openai/v6`, `tracing/openai/v7`
* `tracing/anthropic`
* `tracing/google-genai`, `tracing/google-genai-v2`
* `tracing/vercelai`, `tracing/vercelai/v5`, `tracing/vercelai/v6_v7`
* `tracing/langchain`, `tracing/langchain/v1`
* `tracing/langgraph`
* `aws-serverless/bedrock`

## Twins to fold back

* `tracing/vercelai/span-streaming-v4` and `tracing/vercelai/span-streaming-v6` into the matching vercelai suites
* `tracing/mcp-server-streamed` has no static original, so just drop the suffix

Start with the parent issue's porting recipe, then inspect the listed node integration suites and their span-streaming variants. Pay particular attention to deep gen_ai attributes on child spans, the { value, type } shape, and collecting attributes across envelopes. Fold the specified Vercel AI twins into their matching suites and remove the listed suffix where applicable; the suites should cover the same streaming behavior afterward.

Rédigé par le modèle d'indexation à partir du texte de l'issue.