Errors trying to label a repository with valid chars

Summary

Strange behavior in 'label set' command:

$ pulp python repository label set --key 'osv-dev ecosystem' --value 'test' --repository test-python
Error: {"key":["Enter a valid \"slug\" consisting of letters, numbers, underscores or hyphens."]}

$ pulp python repository label set --key 'osv_dev ecosystem' --value 'test' --repository test-python
Error: {"key":["Enter a valid \"slug\" consisting of letters, numbers, underscores or hyphens."]}

• I think pulp_labels_validator serializer considers space as valid, but this still failed:

$ pulp python repository label set --key 'osv dev ecosystem' --value 'test' --repository test-python
Error: {"key":["Enter a valid \"slug\" consisting of letters, numbers, underscores or hyphens."]}

• not sure how this passed the pulp_labels_validator serializer:

$ pulp python repository label set --key 'osv_dev-ecosystem' --value 'test' --repository test-python
$ pulp python repository show --name test-python |jq .pulp_labels
{
  "osv_dev-ecosystem": "test"
}

Additonal context

From pulpcore code, it seems like space and underscore are allowed, but hyphens are not:
https://github.com/pulp/pulpcore/blob/9b6c47ffa88377de814c47c2ceb0cf819cf6f288/pulpcore/app/serializers/fields.py#L430

Reproduce the three pulp python repository label set examples and compare their behavior with the pulpcore serializer at pulpcore/app/serializers/fields.py around line 430. Trace how the CLI sends the label key, then make validation consistently accept or reject the documented characters and verify the three cases behave as intended.