[4.x]: User Group condition rule is available when there are no user groups

[mattstein]

Description

In the early days of a new Craft 4 project, I might add a Current User Condition to a field layout element with a User Group rule—but if my site doesn’t have any user groups, it’s unclear what I’m supposed to do with the rule’s last field:

The text input makes it seem like maybe I can enter something, but without any suggestions or other hints it may not be clear there’s just nothing I can enter.

To help reinforce the expected usage, the condition rule should either...

• a) include a note that no user groups are available to select (ideally with a link to create one)
• b) not appear in the first place if it’s not a relevant option

Steps to reproduce

1. Start with a Craft site that does not have any user groups.
2. Create some fields and a field layout.
3. Pick a field and add a User Condition with a User Group condition rule.
4. Make sensible choices for each field in the User Group condition rule. (Hint: you can’t.)

Expected behavior

The condition rule would be unavailable if it doesn’t apply, or some UI hint would help me understand there’s nothing to select.

Actual behavior

The rule is available even though I can’t provide any meaningful input.

Craft CMS version

4.0.2

PHP version

8.0.15