Fix shipment adjustments not persisting on order recalculate

[Noah-Silvera]

Summary

A commit was made in #6315 (5979f25) in service of the in memory order updater #5872 that changed the behavior in the OrderTaxation class to set the adjustment value but not persist it. Instead, the persistence happens when the order is saved. If a shipment is changed, and an associated adjustment is changed, the shipment adjustment will be autosaved when the order is.

However, if a shipment is not changed, but the adjustment is, the adjustment will not be autosaved when the order is.

In #6315, we ensured that these changed associations cannot get left behind by setting autosave: true, which forces the model to check if it has any associations that need saving instead of telling it's relation "nope I haven't changed"

We can do the same thing here for the shipment to ensure changing adjustments will make the shipment tell it's order "I have changed", even if none of it's direct properties have changed.

You can test this change by removing the autosave: true option the adjustments and running 'when the address has changed to a different state' specs. They fail with the error "expected order.shipments.first.adjustments.first.amount to have changed from 1 to 2, but did not change", demonstrating a scenario where the shipment adjustment changes do not get persisted.

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[benjaminwil]

Thanks for finding this!

I think it would make sense to release this in a 4.6.1 patch. 💯

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.35%. Comparing base (d070f94) to head (b47e0f0).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6334   +/-   ##
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  Coverage   89.35%   89.35%           
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  Files         961      961           
  Lines       20195    20195           
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  Hits        18046    18046           
  Misses       2149     2149           

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[Noah-Silvera]

I think it would make sense to release this in a 4.6.1 patch. 💯

I thought so too!

[tvdeyen]

Great commit message. This is how it's supposed to be done 👏🏻

[github-actions]

💚 All backports created successfully

Status	Branch	Result
✅	v4.6

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