fix: add missing course filter attribute

[johanseto]

Description

This is used to delete courses.

(cherry picked from commit 1db1bfd)

Context & Issue:
Currently, the course deletion functionality is broken. When attempting to delete a course using Meilisearch, the operation fails because the course attribute is not configured as a filterable parameter within the COURSE_INFO_INDEX.

Solution:
This PR fixes the issue by adding course to the list of filterable attributes for the COURSE_INFO_INDEX https://github.com/openedx/openedx-platform/blob/5439a27f8522d74d63726ec266c0263a3bbfb69b/cms/djangoapps/contentstore/courseware_index.py#L669 , allowing Meilisearch to properly filter and execute the deletion.
https://github.com/openedx/openedx-platform/blob/22512ba78be63fc2c6ffe23637b76f31d1aed656/cms/djangoapps/contentstore/signals/handlers.py#L176

Test

• create an empty course
• check if existence in the Meilisearch site
• delete the course via shell

tutor local run cms ./manage.py cms delete_course <course_id>

• Check the course is deleted in meilisearch

Before

After

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[bradenmacdonald]

Thank you for this fix! Could you please include a version bump to 7.0.3 in edxsearch/__init__.py ?