From your photo, you wont know which one of those green/yellow wires is the gas bond...
One from the main supply cable, one going to water maybe? What are the others?
Leave it connected, as disconnecting the wrong one could cause an issue later on.
If the gas pipe no longer enters the building, and you're removing the pipes within the property.... the bonding cable isn't doing anything..... there's no harm leaving it coiled up somewhere under the floor....
Likewise, there's no harm in removing it systematically from the gas meter position back to the consumer unit as you uncover its route by lifting boards etc.
However, as
@DPG mentions in #2, make sure the gas bond doesn't then loop from the gas pipe onto the water pipe or other service... or you'll be disconnecting both.