git send-email loses annotate changes on error

Hello.

I tried sending a patch using `git send-email -1 --annotate`, and
decided to describe the checks I ran in the annotation. Unfortunately,
the submission failed due to a transient network error:

   Unable to initialize SMTP properly. Check config and use --smtp-
   debug. VALUES: server=smtp.gmail.com encryption=tls
   hello=kaiser.localdomain port=587 at
   /nix/store/d5pdyggxfcbwlk3m59nasnzdm33kdyg7-git-2.26.1/libexec/git-
   core/.git-send-email-wrapped line 1557.

Then I wanted to resubmit the patch but all the changes I made in the
annotate steps were lost, as the tempdir has been cleaned up on exit:

https://github.com/git/git/blob/de49261b050d9cd8ec73842356077bc5b606640f/git-send-email.perl#L685

I am running git version 2.26.1.