Fix cleanup of mocked tags

What does this MR do?

Fix cleanup of mocked tags. The logic in !1703 (merged) missed setting of a variable, which resulted in no mocked tags being cleaned up.

Related issues

Closes #2034 (closed)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

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Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Integration tests added to GitLab QA
• The impact any change in container size has should be evaluated
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