fix: uploading large files saving to disk instead of memory

[frostming]

Signed-off-by: Frost Ming me@frostming.com

What does this PR address?

Fixes #(issue)

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[sauyon]

I think there is a separate issue with building large Bentos on Linux (I think we do actually use temp directory for building?), so I can't test this, but LGTM otherwise.

[frostming]

I think there is a separate issue with building large Bentos on Linux (I think we do actually use temp directory for building?), so I can't test this, but LGTM otherwise.

Yes, let's improve it later. Because usually the bento won't be too large, it is not urgent.

[bojiang]

Tested with 15G models. The speed is acceptable.