fix: Use time instead of vector_timestamp for sorting

The `vector_timestamp` column doesn't have any semantic meaning for the tracking
logs. This removes use of that column (which was renamed to `timestamp`) in favor of
`time` which is the actual event time.

src/ol_dbt/models/staging/mitxonline/stg__mitxonline__openedx__tracking_logs__user_activity.sql

@@ -26,7 +26,7 @@ with source as (
         *
         , row_number() over (
             partition by username, context, event_source, event_type, event, "time"  --noqa
-            order by _airbyte_emitted_at desc, _ab_source_file_last_modified desc, vector_timestamp desc
+            order by _airbyte_emitted_at desc, _ab_source_file_last_modified desc, "time" desc
         ) as row_num
     from source
 )

src/ol_dbt/models/staging/mitxpro/stg__mitxpro__openedx__tracking_logs__user_activity.sql

@@ -26,7 +26,7 @@ with source as (
         *
         , row_number() over (
             partition by username, context, event_source, event_type, event, "time"   --noqa
-            order by _airbyte_emitted_at desc, _ab_source_file_last_modified desc, vector_timestamp desc
+            order by _airbyte_emitted_at desc, _ab_source_file_last_modified desc, "time" desc
         ) as row_num
     from source
 )