upload broken on cloudflare again

[sirpy]

it used to work but now its broken again with latest version

https://github.com/storacha-network/w3up/blob/d4f5f45c4f532769b38f9fb784bebc0e75181b8e/packages/upload-client/src/blob/add.js#L231

cloudflare doesn't support setting the mode: 'cors' verified that removing it solves the issue