Fix typo in UncontrolledAllocationSizeGood.go

Co-authored-by: data-douser <70299490+data-douser@users.noreply.github.com>

Author: Copilot

languages/go/custom/test/UncontrolledAllocationSize/UncontrolledAllocationSizeGood.go

@@ -26,6 +26,6 @@ func OutOfMemoryGood(w http.ResponseWriter, r *http.Request) {
 	for i := 0; i < sink; i++ {
 		result[i] = fmt.Sprintf("Item %d", i+1)
 	}
-	w.Header().Set("Content-Type\", \"application/json")
+	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(result)
 }