[Bug]: typespec-autorest not outputting correct next link name for xml spec

### Describe the bug

Given the following typespec definition:
```
/** The next marker of the blobs. */
@Xml.name("NextMarker") nextMarker?: string;
```

The generated openapi spec doesnt have the right next link name:
```
"x-ms-pageable": {
"nextLinkName": "nextMarker"
}
```

Expected output (use the name specified in the `@Xml.name` decorator):
```
"x-ms-pageable": {
"nextLinkName": "NextMarker"
}
```

### Reproduction

Example above

### Checklist

- [x] Follow our [Code of Conduct](https://github.com/azure/typespec-azure/blob/main/CODE_OF_CONDUCT.md)
- [x] Check that this issue is about the Azure libraries for typespec. For bug in the typespec language or core libraries file it in the [TypeSpec repo](https://github.com/Microsoft/TypeSpec/issues/new/choose)
- [x] Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
- [x] The provided reproduction is a [minimal reproducible example](https://stackoverflow.com/help/minimal-reproducible-example) of the bug.

Start by reproducing the issue with the shown TypeSpec definition in typespec-autorest and inspect the pageable next-link generation path. Confirm that the generated OpenAPI x-ms-pageable nextLinkName uses the @Xml.name value "NextMarker" rather than the property name "nextMarker".

Written by the indexing model from the issue text.