Issue: usage choices are not validated for variadic arguments

[stychu]

When defining a task with a variadic argument (var=#true) and a set of choices, mise does not appear to validate the input against those choices. It allows any value to be passed through to the task, bypassing the expected validation logic.

[tasks.aa]
description = "Run Python unit tests"
usage = '''
arg "<level>" var=#true {
  choices "debug" "info" "warn" "error"
}
'''
run = "echo ${usage_level}"

If I run the task with an invalid choice:
mise run aa "not-a-valid-option"
The task executes and prints not-a-valid-option instead of throwing a validation error.

The CLI should catch that not-a-valid-option is not in the list of allowed choices (debug, info, warn, error) and exit with an error before executing the run script.

It does not make sense to me it being not validated especially --help will generate the possible options and without variadic on it will validate...

mise run aa --help
Usage: aa <level>…

Arguments:
  <level>…
    [possible values: debug, info, warn, error]