Remove unnecessary `pass` in `elif` block `_build_kwargs()` generic wrapper(?)

Not sure why a `pass` is here, given that there is some logic written for that particular `elif` branch: https://github.com/DiamondLightSource/httomo/blob/3276af4c8445a2e4f37806e30c68ca350a014ee3/httomo/method_wrappers/generic.py#L243-L245

but this feels like it's probably not doing anything and thus can be removed.