Latest deprecations

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$  pim .
/usr/bin/pim:429: DeprecationWarning: Gdk.Screen.width is deprecated
  self.Sizes['sWidth'] = screen.width()
/usr/bin/pim:430: DeprecationWarning: Gdk.Screen.height is deprecated
  self.Sizes['sHeight'] = screen.height()
/usr/bin/pim:450: DeprecationWarning: Gtk.Widget.modify_bg is deprecated
  viewport.modify_bg(Gtk.StateType.NORMAL, Gdk.color_parse('#999999'))
/usr/bin/pim:388: DeprecationWarning: Gdk.Cursor.new is deprecated
  self.win.get_window().set_cursor(Gdk.Cursor.new(Gdk.CursorType.BLANK_CURSOR))

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Regarding the cursor: Hopefully addressed with 185fd2a

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Dunno about the background deprecation. Either replacement requires more work, than I'm currently want to invest.
https://lazka.github.io/pgi-docs/Gtk-3.0/classes/Widget.html#Gtk.Widget.override_background_color (was direct replacement for modify_bg)

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Deprecations regarding Gdk.Screen is addressed with 6682138
This bumps the required pygobject version to 3.22 and doesn't respect multi monitor setups