fix: use get_components in m2m_changed signal handler

Using `get_collection_components` does not work in case of post_remove
as the component is already removed from collection and we don't really
need additional filtering as we already have pk_set from the signal.

openedx/core/djangoapps/content_libraries/signal_handlers.py

@@ -20,7 +20,7 @@
     LIBRARY_COLLECTION_DELETED,
     LIBRARY_COLLECTION_UPDATED,
 )
-from openedx_learning.api.authoring import get_collection_components, get_component, get_components
+from openedx_learning.api.authoring import get_component, get_components
 from openedx_learning.api.authoring_models import Collection, CollectionPublishableEntity, Component, PublishableEntity
 
 from lms.djangoapps.grades.api import signals as grades_signals
@@ -182,18 +182,12 @@ def library_collection_entities_changed(sender, instance, action, pk_set, **kwar
         _library_collection_component_changed(instance.component, library.library_key)
         return
 
+    # When action=="post_clear", pk_set==None
+    # Since the collection instance now has an empty entities set,
+    # we don't know which ones were removed, so we need to update associations for all library components.
+    components = get_components(instance.learning_package_id)
     if pk_set:
-        components = get_collection_components(
-            instance.learning_package_id,
-            instance.key,
-        ).filter(pk__in=pk_set)
-    else:
-        # When action=="post_clear", pk_set==None
-        # Since the collection instance now has an empty entities set,
-        # we don't know which ones were removed, so we need to update associations for all library components.
-        components = get_components(
-            instance.learning_package_id,
-        )
+        components = components.filter(pk__in=pk_set)
 
     for component in components.all():
         _library_collection_component_changed(component, library.library_key)