The theme currently hard codes the minimum size of the calendar
menu to make sure there's a designated area for events
(even if there isn't anything currently scheduled).
A side-effect of the hard coded minimum width is that
if the events area is hidden, the menu ends up much
bigger than the calendar. We don't currently ever hide
the events area, but we will in the future.
This commit moves the min-width restriction from the menu
specifically to the events area.
https://bugzilla.gnome.org/show_bug.cgi?id=657082