Every line that you produce is copyrighted by you, automatically. There is no "obviousness" test for copyright: if you decide to code a for loop, then that for loop is copyrighted the moment you type it in.

copilot is outputting literally small chunks of code that needs a lot of cleanup afterwards

If you start from copyrighted chunks, then clean them, you're still violating people's copyright. Multi-million dollar lawsuits have been fought over people using small samples from other people's music, cleaning them, and releasing them as parts of their own song.