[Due for payment 2025-07-10] Add useNewTransaction unit tests

[SzymczakJ]

Add useNewTransaction tests, coming from this discussion.

Issue Owner

Current Issue Owner: @CortneyOfstad

[melvin-bot]

Triggered auto assignment to @CortneyOfstad (Bug), see https://stackoverflow.com/c/expensify/questions/14418 for more details. Please add this bug to a GH project, as outlined in the SO.

[CortneyOfstad]

Hey team! I'm unfamiliar with this type of GH. I checked SO but came up short. Is there any documentation or steps that you can point me to for this? Thanks in advance for any help!