feat(cdc_device): Switch to new VFS API (IEC-400)

[haberturdeur]

Description

In version v5.4 ESP-IDF switched to new VFS API, with smaller memory overhead. Since the previous API will be either deprecated or removed in ESP-IDF v6 this MR updates to the new API.

Related

• Relevant docs

Testing

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Checklist

Before submitting a Pull Request, please ensure the following:

• 🚨 This PR does not introduce breaking changes.
• All CI checks (GH Actions) pass.
• Documentation is updated as needed.
• Tests are updated or added as necessary.
• Code is well-commented, especially in complex areas.
• Git history is clean — commits are squashed to the minimum necessary.

[tore-espressif]

@haberturdeur at this point we can't drop support for IDF < 5.4.
If you plan to remove the old API in esp-idf, that esp_tinyusb must be update so it work with all active esp-idf version.