Description of problem:

I've bisected the issue already and noticed that the issue is related to the @mui/material package updated from 5.15.21 to 5.16.0. Merged with PR https://github.com/janus-idp/backstage-showcase/pull/1379

Starting with 1.2.0, the card text also shows an underline decorator.

Prerequisites (if any, like setup, operators/versions):

None

Steps to Reproduce

1. Just open the Learning path page

Actual results:

1. Starting with 1.2.0 the text has an underline decorator
2. In the main branch there is no spacing/gap between the cards anymore

Expected results:

1. No underline decorator
2. A gap between the cards

Reproducibility (Always/Intermittent/Only Once):

Always

Build Details:

1.2.0
main branch as of today

Additional info (Such as Logs, Screenshots, etc):