fix: drop newlib from PRIV_REQUIRES

[Lapshin]

Description

newlib component is going to be renamed to esp_libc
I don't see reasons for adding the component via PRIV_REQUIRES because it is already in g1_components

If you lack some private newlib headers, I believe they should be made public.

Related

• ESP-IDF MR !41584

Testing

---

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.

[david-cermak]

Thanks for the fixes!