fix: filter labels to list containers (#565)

Description

The current form of the label flag doesn't match the pool containers. Accordingly, filtering does not work correctly.

fmt.Sprintf("--label %s='%s'", LabelClone, c.Pool.Name),

Related issue

!558 (merged)

#565

Examples

Checklist

• MR description has been reviewed
• MR changes are functionally tested
• MR does NOT have API/CLI changes OR there are API/CLI changes and they have been reviewed & DOCS ARE ADJUSTED (reference doc, etc)
• MR does NOT have UI changes OR there are UI changes and they have been reviewed & UX IS REVIEWED