Make updates to the search index sync for libraries

[rpenido]

As we are using the meilisearch index as a source for the lists in the new Library Authoring Home, we need to ensure that the index is always up to date with our model data.

To ensure that, we must move some event handlers related to libraries from async to sync.

We should check the following places:

• https://github.com/openedx/edx-platform/blob/master/openedx/core/djangoapps/content/search/tasks.py
• https://github.com/openedx/edx-platform/blob/master/openedx/core/djangoapps/content/search/handlers.py

[pomegranited]

FYI @rpenido Is this task covered by openedx/openedx-platform#35495 ? It's a drive-by as part of FAL-3825.

[rpenido]

Hi @pomegranited! Thank you for the heads up.
I think it covers pretty much it. I will add a comment there for the method that I think we should also move to sync.