fix tests: update tests in 03-connection, use expected errors

[likesToEatFish]

Description

ref: #7175

Use expected errors in modules/core/03-connection/keeper/

---

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[likesToEatFish]

This PR is handled in keeper and PR #7664 is handled in types so they are not duplicated.

[DimitrisJim]

thanks! Let me take care of merging main, the runners are getting swamped. Thanks!

[DimitrisJim]

Thanks!