computed_settings: Remove deprecated USE_L10N setting.
computed_settings: Remove deprecated USE_L10N setting.

This is deprecated and defaults to True in Django 4.0.

Signed-off-by: Anders Kaseorg <dfdb7392591db597bc41cf266a9c3bc12a2706e5@zulip.com>

andersk/zulip,zulip/zulip,zulip/zulip,rht/zulip,zulip/zulip,rht/zulip,andersk/zulip,andersk/zulip,zulip/zulip,andersk/zulip,zulip/zulip,rht/zulip,rht/zulip,zulip/zulip,andersk/zulip,andersk/zulip,rht/zulip,andersk/zulip,rht/zulip,rht/zulip,zulip/zulip