Reset Bricked Pico
This happens sometimes. Could be because of your code, a glitch, a bug, many things.
The issue likely lies inside the flash memory chip on your Pico board.
Yeah, pretty easily actually. Just follow this link to the official Raspberry Pi website and download their UF2 file for resetting the flash memory. Then hold down the bootsel button while plugging in your PICO to get it into DFU mode, just as if you were going to install CircuitPython but instead you want to drag and drop this flash_nuke.uf2 file into your Pico's root directory instead. When it's finished you should be able to reinstall CircuitPython without any problems.