Support Theme: modwatch warning showing on archived topic

[Clorith]

We've introduced a warning message to users that shows when a post is held for moderation, and after a given period of time it will inform them that it's taking longer than usual to be approved, and invites them to seek us out on Slack.

It seems the message to come see us on Slack is displayed on an archived topic (if this is a one off case I don't know), but it shouldn't be showing (it actually shouldn't be accessible to non-moderators in the first place)

The topic in question, which is archived at this time, ​https://wordpress.org/support/topic/rock-stars-of-idx-for-wordpress/

[SergeyBiryukov]

In 4898:

Support Theme: After [4890], adjust the logic to only show moderation notice for archived posts to moderators.

Fixes #2489. See #2474.