Passing same `--no-...` option twice breaks with bad error message

When running effekt indirectly via a script, it can happen that options like `--no-optimize` get duplicated, e.g.:
```sh
effekt --no-optimize --no-optimize
```

When this happens, Effekt currently errors out with:
```output
Command-line error: Bad arguments for option 'optimize': ' ' - wrong arguments format
Common Options
-c, --compile Compile the Effekt program to the backend
specific representation
--no-compile
...
```

IMHO this should just work, or at least provide a better error message.