I would like to point out that an outside light fixed to the wall of a dwelling, which is not a new circuit, has never been notifiable to building control.
With the January changes, as it will not be a new circuit, it is certainly not notifiable.
Fit the light with the fused spur and inspect, test and certify correctly and you are all good.
If the cable for the lighting is not buried in the wall at any point (e.g. drill through back of socket to outside ) and have surface wiring outside then there is no requirement for RCD protection either.