38da479ee8
`-slider-handle-radius` is a floating point value and even in the default theme it's not a whole number. Regardless of the fractional part that's still going to occupy a whole extra pixel with antialiasing. So make room for it. Otherwise it looks clipped, which it is by the Cairo context of its `StDrawingArea`. Fixes https://gitlab.gnome.org/GNOME/gnome-shell/issues/1569