Add wording for adding, removing labels for package issues

[yeelauren]

Context : https://pyopensci.slack.com/archives/C041M65BW4F/p1718989537035139

From Leah: you can remove the older labels as the issue progresses. so for an on-hold issue - we’d want the label there to represent the most recent step in the review. so if the reviewers are in - you might add that label and remove 1/editor-assigned and 3/reviewers-assigned as those steps are complete