feat: Automatic Vended Credential Refresh

### Feature Request / Improvement

Today, long-running writes to PyIceberg risk failing when credentials expire mid-transaction. The Java implementation addressed this by adding a vended-credential refresh mechanism that calls a REST catalog endpoint to obtain new credentials whenever the current ones are within five minutes of expiring.

I propose a similar approach for PyIceberg, delivered in three separate PRs:

1. **VendedCredential class implementation** (largest diff) -> [PR](https://github.com/apache/iceberg-python/pull/3507) ready for review
2. **Credential refresh support in `PyArrowFileIO`** -> PR pending review and merge of 1
3. **Credential refresh support in `FsspecFileIO`** -> PR pending review and merge of 1

PRs 2 and 3 depend on PR 1, which provides the core vended-credential implementation.

Commencez par examiner PR 3507, qui contient l’implémentation de VendedCredential et constitue la dépendance pour le travail restant. Examinez ensuite la prise en charge prévue de l’actualisation de PyArrowFileIO et FsspecFileIO ; la fonctionnalité sera complète lorsque les deux intégrations actualiseront avant leur expiration les informations d’identification obtenues du catalogue REST.

Rédigé par le modèle d'indexation à partir du texte de l'issue.