In my opinion, never put secrets anywhere near a code repo to begin with. Put them in something like Vault. Also in my opinion, for your own dev work, source

In my opinion, never put secrets anywhere near a code repo to begin with. Put them in something like Vault. Also in my opinion, for your own dev work, source a file well outside of anywhere your code might live that has name=value pairs. Give the file name something highly obscene, long and upper-case that would be obvious if you contemplating committing it. See if your git repo has a policy against a certain file name and use that. People will do what people can do and mistakes happen. :-)