Don't "pub use" modules that contain no public surface area

When building https://github.com/Azure/azure-rest-api-specs/tree/main/specification/schemaregistry/data-plane/SchemaRegistry

In `models/mod.rs`:
```rust
...
pub use header_traits::*;
pub use method_options::*;
...
```
The above modules don't contain any public surface area, i.e. all contents are `pub(crate)`.