fix: remove height and width in screenshots

They aren't needed when images have type set to `source`

Author: tfuxu

data/com.ranfdev.Geopard.metainfo.xml.in.in

@@ -40,13 +40,13 @@
   </description>
 
   <screenshots>
-    <screenshot type="default" height="722" width="1022">
+    <screenshot type="default">
       <image type="source">https://raw.githubusercontent.com/ranfdev/Geopard/master/data/screenshots/1.png</image>
     </screenshot>
-    <screenshot height="752" width="442">
+    <screenshot>
       <image type="source">https://raw.githubusercontent.com/ranfdev/Geopard/master/data/screenshots/2.png</image>
     </screenshot>
-    <screenshot height="752" width="442">
+    <screenshot>
       <image type="source">https://raw.githubusercontent.com/ranfdev/Geopard/master/data/screenshots/3.png</image>
     </screenshot>
   </screenshots>