UV pip install requirements file breaks when it contains `--trusted-host`

I apologize if this is a duplicate issue. I searched #1339 pretty thoroughly as well as #6591.

If you run a command like `uv pip install -r requirements.txt` with a requirements file looking like this, it throws the error: `error: Unexpected '-', expected '-c', '-e', '-r' or the start of a requirement at requirements.txt:1:1`.

```
--trusted-host org.domain.com

custom_package
...
```