Git private branch Feature Suggestion

Hi Git developers,

I have a request for you. Could you please add private branches? This is a really useful thing. Imagine that you want to publish your project as open source, but you need to hide the .env file in a separate repository. It's easier to do everything in one repository, but in a different branch. Maybe there is another way, and I'm just dumb as fuck, but here's another example: Say you don't want to release a new feature yet. To do so, create a private branch, make the feature there, then merge it into the main branch.

Maybe I'm a dumb ass, and don't need to ask this of you, but GitLab, etc., anyway, I'd appreciate it if you could add this feature.