Add `providerMetadata` information to Vercel AI spans

[AbhiPrasad]

[AbhiPrasad]

We'll need upstream changes to do this without monkeypatching. I'd like to keep it that way if possible: vercel/ai#6672

[AbhiPrasad]

Going to track the ai sdk work separately in another issue.

• Use more OTEL semantic conventions with ai OTEL spans vercel/ai#6673
• Add OTEL span attributes for provider metadata vercel/ai#6672