restic: introduce Counter interface to decouple from ui/progress (#21861)

decouple restic and ui/progress packages

internal/repository/testing.go

@@ -167,7 +167,7 @@ func TestNewLock(_ *testing.T, repo *Repository, exclusive bool) (*restic.Lock,
 func TestCheckRepo(t testing.TB, repo *Repository) {
 	chkr := newChecker(repo)
 
-	hints, errs := chkr.LoadIndex(context.TODO(), nil)
+	hints, errs := chkr.LoadIndex(context.TODO(), restic.NoopTerminalCounterFactory)
 	if len(errs) != 0 {
 		t.Fatalf("errors loading index: %v", errs)
 	}
@@ -188,7 +188,7 @@ func TestCheckRepo(t testing.TB, repo *Repository) {
 	errChan = make(chan error)
 	go chkr.ReadPacks(context.TODO(), func(packs map[restic.ID]int64) map[restic.ID]int64 {
 		return packs
-	}, nil, errChan)
+	}, restic.NoopCounter, errChan)
 
 	for err := range errChan {
 		t.Error(err)