Redirect dnf-json stderr to osbuild-composer stderr

When something wrong happens, we want to know about it.

internal/rpmmd/repository.go

@@ -3,6 +3,7 @@ package rpmmd
 import (
 	"encoding/json"
 	"log"
+	"os"
 	"os/exec"
 	"sort"
 	"time"
@@ -43,6 +44,7 @@ func runDNF(command string, arguments []string, result interface{}) error {
 	argv := append([]string{"dnf-json", command}, arguments...)
 
 	cmd := exec.Command("python3", argv...)
+	cmd.Stderr = os.Stderr
 	stdout, err := cmd.StdoutPipe()
 	if err != nil {
 		log.Fatalf("Could not execute dnf-json")