This isn't that strange for a number of open source projects. I don't know Godot's specifics, but lots of folks are willing to toss a few bucks via patreon or other sources. They keep a list of donors who don't mind being named in the source code, and it includes a few companies that make monthly donations. I'm sure they get a number of grants like this one from Epic.
There's a number of mastodon servers where people pay donate monthly to them.