feat(mobile): use tabular figures in backup info card (#24820)

* feat(mobile): use tabular figures in backup info card

during large (initial) backups current non-tabular figures are jumping around the UI, making the UI hard to follow. this change makes sure there’s no jump in text width between e.g. 7888 to 7111

* chore: use const

mobile/lib/widgets/backup/backup_info_card.dart

@@ -53,6 +53,7 @@ class BackupInfoCard extends StatelessWidget {
                       info,
                       style: context.textTheme.titleLarge?.copyWith(
                         color: context.colorScheme.onSurface.withAlpha(isLoading ? 50 : 255),
+                        fontFeatures: const [FontFeature.tabularFigures()],
                       ),
                     ),
                     if (isLoading)