Let m.notice messages mark a room as unread
The typescript conversion of Unread.js in matrix-org/matrix-react-sdk#6241
fixed a 6-year-old typo and stopped messages with msgtype=m.notice from being
counted as unread messages. This makes it very difficult to use rooms dedicated
for bot notices (like RSS or GitHub webhook bots).
Signed-off-by: Tulir Asokan <tulir@maunium.net>
