Here is the page that under a minute of googling helped me find:
https://lists.debian.org/debian-security/
To unsubscribe, enter your e-mail and click the 'unsubscribe' button.
That didn't work? Maybe try taking the advice here:
https://www.debian.org/MailingLists/#subglitches
Short of spamming the entire mailing list (to which, making a
conservative estimate, at least a few hundred people subscribe), you
might want to try mailing the hostmaster if you can't figure out how
to either unsub or make a gmail filter rule.
"someone take my email off the list or I will report it as harassment."
I know this is probably frustrating for you, but lay off the legal
threats. For one thing, if you actually *did* follow through that
almost certainly wouldn't go anywhere, but more to the point
threatening people makes them less inclined to want to help you.
"Unsubscribe me or I will spam your list"
For a number of reasons, that would not be a good idea. One being that
it's almost certainly a violation of Google's ToS, and this would be a
very silly thing to get banned over.
And no, I am in no way affiliated with the Debian project.
--
"If you give me six lines written by the hand of the most honest of
men, I will find something in them which will hang him."
- Cardinal Richelieu