The operating system is totally irrelevant.
All you need is a text editor to create files and an FTP client to upload the files to the web server – any computer using any operating system will be able to handle those functions.
If you have a particular favorite editor or tool, then the question is what OSs does that work with? That’s your choice of systems.
I happen to like Webuilder, that’s the main editor I use at my desk.
If I do updates while working away, it’s whatever FTP client and editor are to hand.
It may be useful to be familiar with CentOS linux. That is one of the most popular systems for web servers and a fair percentage of the internet runs on it.
It’s the free version of commercial RedHat linux and built from the same sources.