Provide an opt-out mechanism to prevent a user from being added to any repo in the future

[Thunderforge]

Is your feature request related to a problem? Please describe.
This bot recently added me to the Readme of a public project that I contributed once to seven years ago. The repo owner did not ask for my permission to be added and I have since asked that I be removed (edit: this is now completed).

I am concerned that other repo owners will use this bot to add me to their project's Readmes without my consent. I don't want this for a number of reasons. Therefore, I want to be able to preemptively prevent that.

Describe the solution you'd like
Provide some sort of opt-out mechanism for users to choose to never be able to be added by this bot.

The list of opted out users should not be publicly visible; a checked in text file to this repo is not a good solution because it defeats the point of privacy (and it would require a pull request for each opt-out, which is burdensome to the repo maintainer).

My ideal solution would be that any user can send a command to the bot. Something like @all-contributors never add me. My second solution would be some sort of web form to fill out.

Describe alternatives you've considered
I searched for a way to have the bot remove me (something like @all-contributors please remove @Thunderforge), but there is no documented command I can send in order to do so. Even if there was, I'm not sure if I'd even have permissions to remove myself. And that places the burden on me to deal with any repo maintainers adding it without my permission.

Additional context
It would be much better if the bot asked for permission from the person in question, perhaps by adding them to the PR as a requested reviewer, and strongly encouraging the repo owner to not merge unless they approve.