Unknown commands in interactive mode display traceback

[andy-maier]

Example:
Type xxx as the command (note the trailing blank):

$ zhmc -n -h <host> -u <user>
Enter password (for user <user> at HMC <host>): 
Enter 'help' for help, <CTRL-D> or ':q' to exit.

Unhandled exception in event loop:
  File "/Users/maiera/virtualenvs/zhmccli312/lib/python3.12/site-packages/prompt_toolkit/buffer.py", line 1923, in new_coroutine
    await coroutine(*a, **kw)
  File "/Users/maiera/virtualenvs/zhmccli312/lib/python3.12/site-packages/prompt_toolkit/buffer.py", line 1740, in async_completer
    async for completion in async_generator:
  File "/Users/maiera/virtualenvs/zhmccli312/lib/python3.12/site-packages/prompt_toolkit/completion/base.py", line 310, in get_completions_async
    async for completion in completer.get_completions_async(
  File "/Users/maiera/virtualenvs/zhmccli312/lib/python3.12/site-packages/prompt_toolkit/completion/base.py", line 186, in get_completions_async
    for item in self.get_completions(document, complete_event):
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/maiera/virtualenvs/zhmccli312/lib/python3.12/site-packages/click_repl/_completer.py", line 257, in get_completions
    self.parsed_ctx = _resolve_context(args, self.ctx)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/maiera/virtualenvs/zhmccli312/lib/python3.12/site-packages/click_repl/utils.py", line 46, in _resolve_context
    name, cmd, args = command.resolve_command(ctx, args)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/maiera/virtualenvs/zhmccli312/lib/python3.12/site-packages/click/core.py", line 1755, in resolve_command
    ctx.fail(_("No such command {name!r}.").format(name=original_cmd_name))
  File "/Users/maiera/virtualenvs/zhmccli312/lib/python3.12/site-packages/click/core.py", line 691, in fail
    raise UsageError(message, self)

Exception No such command 'xxx'.
Press ENTER to continue...
zhmc> xxx