PLT1536/marconi fix utxo test cases

[kayvank]

Fix marconi-chain-index equivalent test as the test criteria is ineffective

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• Branch
  • [ x] Tests are provided (if possible)
  • [x ] Commit sequence broadly makes sense
  • [x ] Key commits have useful messages
  • [x ] Formatting, PNG optimization, etc. are updated
  • [x ] Important changes are reflected in changelog.d of the affected packages
• PR
  • [ ] Self-reviewed the diff
  • [ ] Useful pull request description
  • [ ] Reference the ADR in the PR and reference the PR in the ADR (if revelant)
  • [ ] Reviewer requested

[koslambrou]

I think you need to rebase on main. There's a commit I made which shouldn't be here.