Add dgoulet as a tor package signer

https://lists.torproject.org/pipermail/tor-packagers/2021-August/000127.html

$ gpg2 -k dgoulet@torproject.org
pub   rsa2048/0x42E86A2A11F48D36 2011-05-11 [SC] [expires: 2022-04-08]
      Key fingerprint = B744 17ED DF22 AC9F 9E90  F491 42E8 6A2A 11F4 8D36
uid                   [ unknown] David Goulet <dgoulet@ev0ke.net>
uid                   [ unknown] David Goulet <dgoulet@torproject.org>
uid                   [ unknown] David Goulet <dgoulet@riseup.net>
sub   rsa4096/0x2AC6036C93CC198D 2013-09-10 [E] [expires: 2022-04-08]