feat: add Sarvam AI as a transcription provider

[Mrinank-Bhowmick]

Background

This PR adds support for Sarvam AI as a transcription provider in the Vercel AI SDK.

fixes - #6042

Summary

Took references from the ElevenLabs and Deepgram implementations of transcription.

Verification

import { createSarvam } from '@ai-sdk/sarvam';
import { experimental_transcribe as transcribe } from 'ai';
import { readFile } from 'fs/promises';

const sarvam = createSarvam({
  headers: {
    'api-subscription-key': '',
  },
});

const main = async () => {
  const result = await transcribe({
    model: sarvam.transcription('saarika:v2'),
    audio: await readFile('./src/transcript-test.mp3'),
    providerOptions: {
      sarvam: {
        language_code: 'en-IN',
      },
    },
  });

  console.log(result.text.toLowerCase());
};

main();

Output -

hello from the versal aisdk.

Tasks

• Tests have been added / updated (for bug fixes / features)
• Documentation has been added / updated (for bug fixes / features)
• A patch changeset for relevant packages has been added (for bug fixes / features - run pnpm changeset in the project root)
• Formatting issues have been fixed (run pnpm prettier-fix in the project root)

Future Work

Related Issues

#6042

[lgrammel]

Thank you - I'd prefer if you could host and publish it in your own github repo and npm package. Happy to add it as a community provider in our docs!