Delete temp file before running backup (#6248)

(cherry picked from commit b4d148bdb0)

internal/manager/manager.go

@@ -322,6 +322,11 @@ func (s *Manager) BackupDatabase(download bool) (string, string, error) {
 		backupPath = f.Name()
 		backupName = s.Database.DatabaseBackupPath("")
 		f.Close()
+
+		// delete the temp file so that the backup operation can create it
+		if err := os.Remove(backupPath); err != nil {
+			return "", "", fmt.Errorf("could not remove temporary backup file %v: %w", backupPath, err)
+		}
 	} else {
 		backupDir := s.Config.GetBackupDirectoryPathOrDefault()
 		if backupDir != "" {