I deleted my light source... now my bakes look pitch black If i remember correctly, if you deleted your only light source in a scene, blender would automatically light everything related to bakes as seen in the image below

apparently, if you delete your only light source in a scene on blender 2.9, your bakes will be pitch black as seen in the image below

I'm quite new to blender 2.9 and i don't really know how to fix this without adding a new light source, which is exactly what I'm trying to avoid because i want the results as seen in the first image
This s not related to Version 2.9 or 2.x
When you bake combined you should have a source light , or just uncheck Direct and in direct light or just bake Defuse as moonboos mentioned :)