fix: remove --version from subcommands - #1359

The `--version` should be a root option. There is no need to print it
in subsequent subcommands.
For instance, it used to be printed here:

```
$ ilab config --help
Usage: ilab config [OPTIONS] COMMAND [ARGS]...

  Command Group for Interacting with the Config of InstructLab.

  If this is your first time running ilab, it's best to start with `ilab init`
  to create the environment.

Options:
  --version  Show the version and exit.
  --help     Show this message and exit.
```

We only need `ilab --version`.

Signed-off-by: Sébastien Han <seb@redhat.com>