fix(sdk): fix excessive exception handling in sandbox.write

[Eugene Yurtsev (eyurtsev)]

• Let unhandelled exceptions to bubble up, instead of present them to the LLM.
• Absorb responsibility of creating parent folder to upload_files so it can be optimized.

[codspeed-hq]

Merging this PR will not alter performance

✅ 32 untouched benchmarks
⏩ 15 skipped benchmarks¹

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_{Comparing eugene/fix_sandbox_api (e0e8291) with main (e7578dc)}

Footnotes

1. 15 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩