Issue #3590125: Declare xls_serialization 2.x dependency in info.yml

Summary

Mirror the constraint that already lives in composer.json (drupal/xls_serialization: ^2.1) into views_data_export_excel.info.yml so the requirement is surfaced by Drupal's module install UI and dependency checker, not only by Composer.

Change

 dependencies:
   - views_data_export:views_data_export
-  - xls_serialization:xls_serialization
+  - 'xls_serialization:xls_serialization (>=2.1)'

Same lower bound as the composer constraint. Single-quoted because the dependency entry now contains a space and parentheses, matching the convention used by other contrib modules (e.g. domain_shorturl, jquery_ui_*).

Test plan

• Install views_data_export_excel on a site that has xls_serialization 1.x installed: module install fails with a clear dependency-version error instead of silently breaking at runtime.
• Install on a site with xls_serialization >= 2.1: install succeeds, no behaviour change.