Auto merge of #115323 - onur-ozkan:curl-download-checksum-fix, r=Mark-Simulacrum

avoid stdout redirection on `curl` executions

Avoid redirecting the curl output directly to the stdout. This alteration affects the integrity of the file during the retry process, as it also redirects the logs from the retries. Consequently, this leads to the bootstrap process failing because of an invalid checksum.

For more information, see the [zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/326414-t-infra.2Fbootstrap/topic/checksum.20errors)

Fixes #115275

Author: bors