You likely already know that, but to anyone else interested: a good way to prevent these kinds of situations is to run 'nosey parker' on your git repo before pushing it to a remote. It will dig through your code and configs, looking at files and through all the git history, and highlight anything that looks like tokens, passwords, keys, etc. You can set it as a pre-commit hook to block the offending code from even being committed.

https://github.com/praetorian-inc/noseyparker