[Bug]: tsp-spector returns different values for pageables and LROs on Windows and Linux

### Describe the bug

On Windows, next page link is returned as `http://localhost:3000/.../.../`. On Linux, the same link is `http://localhost/.../.../`.
On both OSes, server does indeed run on port 3000.

Same for "operation-location" header value for LROs.

That is why when writing tests, we have to add an extra step to modify the actual value to either drop ":3000", or to add it after "localhost", so that we can use the same expected value, and the test would pass when ran on either platform.

### Reproduction

1. `tsp-spector server start ./../../node_modules/@typespec/http-specs/specs ./../../node_modules/@azure-tools/azure-http-specs/specs`

2. `GET http://localhost:3000/payload/pageable/server-driven-pagination/link HTTP/1.1` - see the value of "next" in the response body.

It repros for every nextPage link or LRO, no need to look into that specific one.

### 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 running the provided `tsp-spector server start` command and the pageable reproduction on both Windows and Linux. Compare the `next` response value and the LRO `operation-location` header, then trace the tsp-spector server's URL construction. Done means both platforms return equivalent localhost URLs including port 3000, with the relevant tests passing consistently.

Written by the indexing model from the issue text.