data: Update custom close icon

The existing asset has a nice black rectangle on top of the
intended shape.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1640>

data/theme/window-close-24-symbolic.svg

@@ -5,39 +5,11 @@
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:svg="http://www.w3.org/2000/svg"
    xmlns="http://www.w3.org/2000/svg"
-   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
-   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
    width="24"
    height="24"
    viewBox="0 0 6.3499999 6.3500002"
    version="1.1"
-   id="svg59656"
-   sodipodi:docname="window-close-24-symbolic.svg"
-   inkscape:version="1.0.1 (3bc2e813f5, 2020-09-07)">
-  <sodipodi:namedview
-     pagecolor="#ffffff"
-     bordercolor="#666666"
-     borderopacity="1"
-     objecttolerance="10"
-     gridtolerance="10"
-     guidetolerance="10"
-     inkscape:pageopacity="0"
-     inkscape:pageshadow="2"
-     inkscape:window-width="1920"
-     inkscape:window-height="1016"
-     id="namedview9"
-     showgrid="true"
-     inkscape:zoom="2.4967968"
-     inkscape:cx="-99.100336"
-     inkscape:cy="-39.762752"
-     inkscape:window-x="0"
-     inkscape:window-y="0"
-     inkscape:window-maximized="1"
-     inkscape:current-layer="svg59656">
-    <inkscape:grid
-       type="xygrid"
-       id="grid901" />
-  </sodipodi:namedview>
+   id="svg59656">
   <defs
      id="defs59650" />
   <metadata
@@ -52,20 +24,8 @@
       </cc:Work>
     </rdf:RDF>
   </metadata>
-  <g
-     id="g905">
-    <rect
-       style="color:#bebebe;display:inline;overflow:visible;visibility:visible;fill:none;stroke:none;stroke-width:0.264583;marker:none;enable-background:new"
-       id="rect10837-5"
-       y="0"
-       x="0"
-       height="6.3499999"
-       width="6.3499999" />
-    <path
-       sodipodi:nodetypes="ccsccccccccccccccccccccccc"
-       style="color:#bebebe;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:medium;line-height:normal;font-family:'Andale Mono';-inkscape-font-specification:'Andale Mono';text-indent:0;text-align:start;text-decoration:none;text-decoration-line:none;letter-spacing:normal;word-spacing:normal;text-transform:none;writing-mode:lr-tb;direction:ltr;text-anchor:start;display:inline;overflow:visible;visibility:visible;fill:#241f31;fill-opacity:1;fill-rule:nonzero;stroke:none;stroke-width:0.471289;marker:none;enable-background:new"
-       id="path10839-9"
-       inkscape:connector-curvature="0"
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-  </g>
+  <path
+     style="color:#bebebe;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:medium;line-height:normal;font-family:'Andale Mono';-inkscape-font-specification:'Andale Mono';text-indent:0;text-align:start;text-decoration:none;text-decoration-line:none;letter-spacing:normal;word-spacing:normal;text-transform:none;writing-mode:lr-tb;direction:ltr;text-anchor:start;display:inline;overflow:visible;visibility:visible;fill:#241f31;fill-opacity:1;fill-rule:nonzero;stroke:none;stroke-width:0.471289;marker:none;enable-background:new"
+     id="path10839-9"
+     d="m 1.5875,1.5875 h 0.2645834 c 0.00274,-3.18e-5 0.0055,-1.217e-4 0.00827,0 0.067456,0.00296 0.1349031,0.03402 0.181901,0.082682 L 3.1758323,2.8029916 4.3160156,1.670182 C 4.3862956,1.609196 4.4341976,1.589352 4.4979166,1.5875 H 4.7625 v 0.264583 c 0,0.075795 -0.00909,0.1456928 -0.066146,0.1984375 L 3.5644391,3.175 4.688086,4.3077474 C 4.737877,4.3575344 4.762498,4.4277227 4.7625,4.4979167 V 4.7625 H 4.4979167 C 4.4277225,4.7624974 4.3575325,4.7378673 4.3077475,4.6880859 L 3.1758323,3.5554004 2.0422526,4.688086 C 1.9924676,4.737878 1.9222747,4.7625 1.8520834,4.7625 H 1.5875 V 4.4979168 c -8e-7,-0.070191 0.024622,-0.1403827 0.074414,-0.1901693 L 2.7954938,3.175 1.6619141,2.0505208 C 1.6061553,1.9990249 1.581703,1.9263651 1.5875,1.8520833 Z" />
 </svg>