`pre_release()`: show errors from `devtools::check_win_devel()`

[pat-s]

Currently we call it with quiet = TRUE. I just got a

Error in curl::curl_fetch_memory(url, handle = h) : 
  Failed FTP upload: 550

when calling it non-quiet. This may happen occasionally due to winbuilder issues. We should report this to the user - make the call verbose?

[krlmlr]

We're using callr::r_bg() to run in non-interactive mode in the background. We can check the exit code of the process, available via (I think) checks$get_exit_code().

Maybe expose a function that runs in the background in non-interactive mode and returns an object that prints the exit status?

For CI runs we don't need r_bg(), we can wait until successful submission.

[krlmlr]

Needs {tasq}.

[maelle]

could it (this, and other checks) be a job in the release PR, with a nice summary https://github.blog/2022-05-09-supercharging-github-actions-with-job-summaries/

[maelle]

with some way to re-launch the winbuilder check

[krlmlr]

It seems to me that the original issue was about getting errors if the submission to winbuilder failed. Retrieving the error logs is a neat idea too, let's try that first locally (in a separate issue, with foghorn?) before considering GHA workflows.