[REF] move calculation of migrationInfo into the function that uses it

[eileenmcnaughton]

Overview

Very minor code cleanup

Before

Less readable

After

More readable

Technical Details

This doesn't make a lot of sense as a passed parameter & it's better to derive it closer to where it's used.

It's also kinda silly....

Comments

[civibot]

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[seamuslee001]

Change seems to make sense there should be enough test coverage here that we are would see any failures from this