magnifier: Removed unused get*Color() methods

They use API from Clutter.Rectangle which hasn't been used in the
magnifier since commit c815979f, and has since been removed from
Clutter altogether.

Since the methods are unused, remove them instead of fixing them.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2037>

js/ui/magnifier.js

@@ -407,21 +407,6 @@ export class Magnifier extends Signals.EventEmitter {
         }
     }
 
-    /**
-     * getCrosshairsColor:
-     * Get the color of the crosshairs.
-     *
-     * @returns {string} The color as a string, e.g. '#0000ffff' or 'blue'.
-     */
-    getCrosshairsColor() {
-        if (this._crossHairs) {
-            let clutterColor = this._crossHairs.getColor();
-            return clutterColor.to_string();
-        } else {
-            return '#00000000';
-        }
-    }
-
     /**
      * setCrosshairsThickness:
      *
@@ -1928,16 +1913,6 @@ class Crosshairs extends Clutter.Actor {
         this._vertBottomHair.background_color = clutterColor;
     }
 
-    /**
-     * getColor:
-     * Get the color of the crosshairs.
-     *
-     * @returns {ClutterColor} the crosshairs color
-     */
-    getColor() {
-        return this._horizLeftHair.get_color();
-    }
-
     /**
      * setThickness:
      *