[Cashtab] Drop test causing problems in CI

Summary: Not precisely sure what causes this to fail in CI but it is likely related to the special character used in the formatting. We do not really need this test to confirm expected behavior in Cashtab. So, drop it.

Test Plan: npm test

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D17803