Repairing a notched rafter in a truss roof
Roof trusses tend to be highly engineered and not designed to be altered, and I don't consider myself knowledgeable enough to know exactly how dangerous this is. My suspicion is that you've reduced the possible load your roof can support which would be an issue in strong windows for heavy snow.

The typical solution is to sister another board onto this one. To transfer the load, you'd want it fairly long, several feet to each side, the longer the better. Put some construction adhesive on the current rafter, clamp the sistered board on tight, and screw it with a bunch of 2.5" screws (I'd probably put one every 8" with 2 on each end). That's likely over engineered, but you're better off overdoing the solution than underdoing it and having it fail later.