Advanced Search accordion, updates class name for lighter accordion

[vingle]

The advanced search page is two template files - both adopted a combination of the new <details> accordion pattern with the old classnames during the Dec23 sprint. The other template file was fixed in #29704, this one was missed because it only appears on a search for .crm-master-accordion-header and the visual impact in Greenwich is tiny (in other themes it stands out more).

Before

Old classname. Barely noticeable via the bold text:

After

New classname. Text follows same appearance as other lighter style accordions.

Comments

I missed this in that last PR, sorry - the visual difference is tiny, but from a theming perspective this change should mean all of the old css accordion classnames aren't being used any more by core.

[civibot]

🤖 Thank you for contributing to CiviCRM! ❤️ We will need to test and review this PR. 👷

Introduction for new contributors...

• If this is your first PR, an admin will greenlight automated testing with the command ok to test or add to whitelist.
• A series of tests will automatically run. You can see the results at the bottom of this page (if there are any problems, it will include a link to see what went wrong).
• A demo site will be built where anyone can try out a version of CiviCRM that includes your changes.
• If this process needs to be repeated, an admin will issue the command test this please to rerun tests and build a new demo site.
• Before this PR can be merged, it needs to be reviewed. Please keep in mind that reviewers are volunteers, and their response time can vary from a few hours to a few weeks depending on their availability and their knowledge of this particular part of CiviCRM.
• A great way to speed up this process is to "trade reviews" with someone - find an open PR that you feel able to review, and leave a comment like "I'm reviewing this now, could you please review mine?" (include a link to yours). You don't have to wait for a response to get started (and you don't have to stop at one!) the more you review, the faster this process goes for everyone 😄
• To ensure that you are credited properly in the final release notes, please add yourself to contributor-key.yml
• For more information about contributing, see CONTRIBUTING.md.

Quick links for reviewers...

• ➡️ PR Demo site (can be rebuilt with the command test this please).
• 📖 Review standards
• 🗒️ Review template (brief or verbose)

➡️ Online demo of this PR 🔗

[eileenmcnaughton]

test fails unrelated