fix: override FORUM_SEARCH_BACKEND

The Tutor forum plugin hardcodes FORUM_SEARCH_BACKEND to Meilisearch,
so we need to override it here,
otherwise the forum will continue to use Meilisearch.

Private-ref: https://tasks.opencraft.com/browse/BB-9975

Author: samuelallan72

README.rst

@@ -76,6 +76,7 @@ This plugin provides the following settings to Open edX components for integrati
 
 - (common) ``TYPESENSE_ENABLED: bool = True`` - whether the Typesense backend is enabled
 - (common) ``TYPESENSE_COLLECTION_PREFIX: str = "the_configured_collection_prefix"`` - a prefix that the backend should use for all collections (the API key is scoped to this prefix)
+- (common) ``FORUM_SEARCH_BACKEND = "forum.search.typesense.TypesenseBackend"`` - necessary to override Tutor's default forum search backend value pointing to Meilisearch
 - (cms, lms) ``TYPESENSE_URL: str = "http://typesense:8108"`` - the internal url for accessing the Typesense API
 - (cms, lms) ``TYPESENSE_PUBLIC_URL: str = "http://(depends on TYPESENSE_PUBLIC_HOST)"`` - the public url to the Typesense API (for user searches on the frontend)
 - (cms, lms) ``TYPESENSE_API_KEY: str = "the api key"`` - an api key for the Open edX backend to make updates to Typesense collections

tutor_typesense/patches/openedx-common-settings

@@ -1,2 +1,3 @@
 TYPESENSE_ENABLED = True
 TYPESENSE_COLLECTION_PREFIX = "{{ TYPESENSE_COLLECTION_PREFIX }}"
+FORUM_SEARCH_BACKEND = "forum.search.typesense.TypesenseBackend"