This was removed in Django 4.0 except in historical migrations. We
might as well replace it everywhere.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Generated by `pyupgrade --py3-plus --keep-percent-format` on all our
Python code except `zthumbor` and `zulip-ec2-configure-interfaces`,
followed by manual indentation fixes.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
This change makes it possible for users to control the notification
settings for wildcard mentions as a separate control from PMs and
direct @-mentions.