When I try to quick edit in texture paint I get an error saying that it couldn't find an image editor even though there is one (see photo)

Change the image editor to the executable C:\Program Files\Krita (x64)\bin\krita.exe (or where you have installed Krita)
I had a different issue when I got that error. For me, it had an issue with the parenthesis, so I simply renamed the ...\Krita (x64)\... to ...\Kritax64\...