`-Zbindeps` isn't supported - cargo update works fine with it

```
theo@Theos-MacBook-Pro rust % cargo upgrade -i -Z bindeps
error: invalid value 'bindeps' for '-Z '

For more information, try '--help'.
```

Start at the cargo upgrade command's option parsing and compare how it handles the -Z bindeps flag with cargo update. Reproduce the reported command, then trace the argument forwarding and add a regression test showing that cargo upgrade accepts bindeps and behaves consistently with cargo update.

Written by the indexing model from the issue text.