Improve language runtime detection for SDK

[mlejva]

Currently, we're a bit naive when detecting a language runtime. We only detect if it's a browser or Node.

The platform library we're using isn't able to detect well other runtimes besides Node

Relevant code:

E2B/packages/js-sdk/src/api/metadata.ts

Line 10 in bd3b5b9

lang_version: platform.version || 'unknown',

E2B/packages/js-sdk/src/api/metadata.ts

Line 13 in bd3b5b9

sdk_runtime: typeof window === 'undefined' ? 'node' : 'browser',

Describe the solution you'd like
We should be able to detect at least Node, Deno, and Bun.