feat(AR): Add one-off holidays#541

This pull request updates and reorganizes the holiday data for Argentina (`data/countries/AR.yaml`) with the following changes: **Key changes:** 1. **Addition of one-off holidays:** * Added the previously missing National Census holidays for the years: * `1980-10-22` (National Census 1980) * `1991-05-15` (National Census 1991) * `2001-11-17` (National Census 2001) * Added the special national holiday declared on `2022-12-20` to celebrate Argentina's victory in the FIFA World Cup QATAR 2022. 2. **Reorganization of one-off holidays:** * Existing one-off bicentennial holidays and the more recent census holidays (2010, 2022) have been moved from their inline chronological positions. * These are now grouped into two new dedicated sections at the end of the file: * `# Special public holiday` (for bicentennials, World Cup celebration, etc.) * `# National Census` (for all census-related holidays) 3. **Updates to bridge holidays (2023-2025):** * The `@source` URLs for bridge holidays in 2023, 2024, and 2025 have been updated to point to more direct and current official government decrees or announcements. **Reasoning for changes:** * **Completeness & accuracy:** To include historical census holidays and the significant 2022 World Cup celebration holiday according to official sources. * **Improved readability & maintainability:** Moving non-recurring, historical holidays to separate sections at the end of the file makes the main list of regular, ongoing holidays cleaner, easier to follow, and less cluttered. Grouping census days also improves organization. * **Source integrity:** Ensuring that source URLs are up-to-date and reliable, and that data reflects these sources. These changes aim to enhance the accuracy, completeness, and usability of Argentina's holiday data in this project. Please review these additions, reorganizations, and updates. Let me know if you have any questions or require further adjustments. Thanks!