The short answer; anyone who wants to call themselves as such regardless of gender, sexual orientation, skin color, religious belief, or anything else.
The long answer; witchcraft is a practice. It's like working on a car or painting in your free time, it has no obligations outside of having an interest in doing the thing then taking the time and energy to learn and practice.
But that only goes for witchcraft. Elements of the craft can be incorporated into other things such as Wicca, like I talked about last week, and in those cases there may be other requirements such as a period of study time before you can take a title or an initiation of some kind but those are specific to those religious practices and not to witchcraft as a whole.
Also, some people believe that the word 'witch' can only apply to cis women but that's not true. Men, trans women and non-binary people can use the term witch too, they don't have to use male terms like wizard or warlock or whatever else. Your gender does not mean you can't call yourself a witch if you practice the craft, end of story. Can you choose to do that if you want to? Absolutely. I know many people are trying to reclaim warlock from its less than favorable connotations. But I also know plenty who would like to say they are a witch but fear doing so because they don't meet what they think or have been told the standards are.
And your current religious practice does not also mean you can't practice witchcraft. There may be restrictions, for example I met a Jewish witch once while I had a small tarot shop on a virtual pet website who asked me kindly to keep the reading to the past and present and not to tell the future, because their religious path within Judaism said that only God may know the future and it is not for man to have such insights but outside of that and banning the practice of necromancy or anything to do with the dead they explained that there is nothing prohibiting them from practicing witchcraft. They simply believed that instead of the power of their herbs or spell jars coming from nature or their own energy it all came from God.
So like I said, in short if you wish to use the term 'witch' for yourself there is nothing stopping you from doing so and you don't have to think there is. You don't have to be some skinny white cis girl, you can be chubby and poc and trans and whatever else you want to call yourself in all those terms and still be a witch and if anyone tries to tell you otherwise it's highly likely they either a) don't know what they're talking about, b) are referring to something else within witchcraft like Wicca or other religious practices that do not apply to witchcraft as a greater whole or c) are the kind of nasty gatekeeper people most of the rest of us don't want in the community anyway.
As I said, keep in mind that religious aspects that incorporate witchcraft may have different requirements to take that title. But if you want to get into it and start calling yourself a witch without any of that business feel free to start using the term. Even if you don't practice often or only do so in your spare time or whatever you're still a witch if you feel like calling yourself that. Even if you're calling yourself a witch as a phase in your life because of some popular culture thing and aren't super deep into it you're still a witch.