stacks: fix flaky stackruntime tests

[liamcervante]

This PR updates all the stackruntime tests to use the consistent sorting I introduced for some of my tests earlier.

Previously, we were sorting the test outputs based on the %T representation of their type. If we had two events of the same type this meant the results weren't deterministic. I introduced the appliedChangeSortKey and plannedChangeSortKey functions in an earlier PR. These sort by the unique addresses of each event type, and so are truly deterministic.

Here's an example of a flake, fixed with a retry:

• https://github.com/hashicorp/terraform/actions/runs/7974971451/attempts/1
• https://github.com/hashicorp/terraform/actions/runs/7974971451/attempts/2

I didn't think any of the other tests were producing two changes of the same type so I didn't update them previously. Now, I just blanket replaced everything.

[github-actions]

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[github-actions]

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