streams: Remove require_active in access_stream code path.

This was confusingly doing an assertion about the subscription being
active, not the channel. We could rename it to
require_active_subscription. But it was only passed with a non-default
value in b2cb443d24, and that call was
removed in 378062cc83.

analytics/views/stats.py

@@ -185,7 +185,6 @@ def get_chart_data_for_stream(
     stream, ignored_sub = access_stream_by_id(
         user_profile,
         stream_id,
-        require_active=True,
         require_content_access=False,
     )