Remove reset to firmware command

[jackpot51]

This was implemented in system76/qmk_firmware@a1ab70c to make the flashing process easier.

However, this increases the risk that malicious keyboard firmware is installed without the user's consent. Therefore, remove the reset command and require the reset keycode (Fn+Esc) to be pressed, or the boot magic code (Esc while plugging in the keyboard) to reboot to the bootloader.

The risk is even higher when using an OS that does not require administrator privileges to access USB devices, such as Windows. And since we, by design so the user can customize things, do not have signed firmware - this means any application could potentially reflash the keyboard firmware.

By requiring a physical keypress to reboot the bootloader, at least the user will have to intentionally set the keyboard into this mode before firmware can be written.

[jackpot51]

The firmware has been adjusted to require a manual unlock before it can be reset to bootloader and flashed.