[Bug]: ⚡ Fix holiday fetching URL and add alternative provider

[PPeitsch]

Guidelines

• I have searched for similar issues before creating this one

Browser

No response

Operating System

Ubuntu

Python Version

3.12

Database

PostgreSQL

Bug Description

The holiday fetching URL (argentina.gob.ar/interior/...) is returning a 404 error for the years 2026 and 2027. It appears the URL structure has changed to argentina.gob.ar/jefatura/....
Additionally, the reliance on a single source (HTML scraping of the government site) makes the system fragile to these URL changes. We need to update the URL and implement a more robust alternative provider (ArgentinaDatos API) to ensure data availability.

Steps to Reproduce

1. Attempt to sync or fetch holidays for the year 2026 or 2027.
2. Check the logs for 404 errors.

Expected Behavior

The system should successfully fetch holidays for upcoming years (2026, 2027). If the primary source is unavailable or changed, it should fallback to an alternative API or handle the error gracefully without breaking the flow.

Relevant Logs

Error fetching holiday data for year 2026: 404 Client Error: Not Found for url: https://www.argentina.gob.ar/interior/feriados-nacionales-2026
⚠️ No se encontraron feriados para 2026.
Error fetching holiday data for year 2027: 404 Client Error: Not Found for url: https://www.argentina.gob.ar/interior/feriados-nacionales-2027
⚠️ No se encontraron feriados para 2027.