Side projects can be invigorating if you can find something you've always wanted to build.

I know GPT-4 in particular has made exploring new, small projects fairly easy.

You could do something similar. Mix up the tediousness of doing the same thing day after day. Or find ways to automate certain portions of your work, if possible. I always get a kick out of that.

Or talk to your boss and explain the problem. You could explore switching things up a bit. That's always an option as well.