Electric wiring in a kitchen island
Depending on your jurisdiction and building permit, you may be obliged to install an outlet.

If you're legally permitted to not have one, then just cap the wires in a closed approved junction box that is 'accessible' within the cabinet. (I put accessible in quotes because it doesn't have to be really easy to get to... just don't put it somewhere -- like underneath the toekick -- that requires actual disassembly for access.)

Do the future you a favor and don't cut the wire back.