You can use Creative Commons. You’ll still have the copyright to the work, so you can relicense it or do whatever you like with it, but they’ll have a particular and proscribed set of things they are guaranteed to be able to do with it into perpetuity.
Choose whichever license suits what you’d like to be able to grant them, in terms of whether they have to credit you for it, whether they’re allowed to modify it, and so on. CC BY lets them do whatever they want, as long as they credit you, which is a common permissive option.
It might not end the Gaza genocide. It will also not cure cancer, end climate change, or stop political violence in the United States. However, electing Harris will produce a hugely better outcome on all of those fronts than will electing Trump.
If you care about the Palestinian people, and you’re risking Trump getting into power again, you don’t actually care about the Palestinian people. You just enjoy grandstanding gestures, and while you’re making your gestures, you’re flirting with making their already horrifying situation absolutely infinitely worse.