I wouldn't pitch the fork just yet until you get a professional assessment at a bike shop. You could gently tap on the fork for several centimeters around the wound and listen for a change in the quality of the tone nearer the scratch. If present I wouldn't ride until a better assessment is completed. That said, neither would I call this little test reason enough for comfort if nothing was heard.
Here's an interesting trick I recently read about. Apparently, helicopter mechanics use this technique to fill/repair chips in rotor blades. If one takes liquid cyanoacrylate glue ("super glue," "Krazy glue," etc.) Fills the basin of a scratch or chip and then immediately sprinkles a generous coating of baking SODA onto the wet glue, it dries and hardens in seconds. The resulting dried cyanoacrylate-baking soda filler is extremely hard, sandable and paintable.
I've used this trick when I want a super glue application to be dry almost immeadiately. An improvised chain tool pin I fashioned from a screw tip bit has been held securely within the threaded pusher of the tool. Still solid after
a half-dozen chain breaks