Handle deleted IOC and old comfigs

[FreddieAkeroyd]

Description of work

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To test

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Acceptance criteria

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Code Review

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• Has the author taken into account the multi-threaded nature of the code?
• Have the changes been recorded appropriately in a PR for release notes?
• Has the manual system tests spreadsheet been updated?

Functional Tests

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Final steps

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• Reviewer has merged the associated PR for the release notes