refactor: improve file closing error handling

main.go

@@ -26,7 +26,13 @@ func main() {
 		fmt.Printf("Error opening %s: %v\n", eventPath, err)
 		os.Exit(1)
 	}
-	defer eventFile.Close()
+	defer func() {
+		closeFileErr := eventFile.Close()
+		if closeFileErr != nil {
+			fmt.Println("Error closing eventFile")
+			os.Exit(1)
+		}
+	}()
 
 	var event GithubEvent
 	decoder := json.NewDecoder(eventFile)