Make a list of email addresses suitable for surveying all Toolforge
maintainers + Cloud VPS project admins.

$ python3 make-toolforge-email-list.py > emails.txt
$ python3 make-cloudvps-email-list.py >> emails.txt
$ sort emails.txt | uniq > all-emails-sorted.txt
$ python3 make-opt-out-list.py | sort | uniq > opt-out.txt
$ grep -vxF -f opt-out.txt all-emails-sorted.txt > emails.txt