Remove color-scheme additions (added in d880133).

We decided to store this in the xapp schema instead.

Author: mtwebster

libcinnamon-desktop/cdesktop-enums.h

@@ -202,13 +202,6 @@ typedef enum
   C_DESKTOP_STYLUS_BUTTON_ACTION_FORWARD
 } CDesktopStylusButtonAction;
 
-typedef enum
-{
-  C_DESKTOP_COLOR_SCHEME_DEFAULT,
-  C_DESKTOP_COLOR_SCHEME_PREFER_DARK,
-  C_DESKTOP_COLOR_SCHEME_PREFER_LIGHT,
-} CDesktopColorScheme;
-
 typedef enum
 {
 /* All bindings before _SEPARATOR are treated as

schemas/org.cinnamon.desktop.interface.gschema.xml.in

@@ -293,13 +293,6 @@
       <default>false</default>
       <summary>Prefer variant names instead of country codes when showing keyboard layouts.</summary>
     </key>
-    <key name="color-scheme" enum="org.cinnamon.desktop.CDesktopColorScheme">
-      <default>'default'</default>
-      <summary>Color scheme</summary>
-      <description>
-        The preferred color scheme for the user interface. Valid values are “default”, “prefer-dark”, “prefer-light”.
-      </description>
-    </key>
     <key name="high-contrast" type="b">
       <default>false</default>
       <summary>Use a high contrast icon and application theme.</summary>