revise screenshots

maybe they'll pass the flathub guidelines this time

Author: jcupitt

org.libvips.vipsdisp.json

@@ -456,7 +456,7 @@
                 {
                     "type" : "git",
                     "url" : "https://github.com/jcupitt/vipsdisp.git",
-                    "tag" : "v3.1.0-4"
+                    "tag" : "v3.1.0-5"
                 }
             ]
         }

org.libvips.vipsdisp.metainfo.xml

@@ -65,6 +65,14 @@ and it has a range of useful visualisation tools and display modes.
 
   <releases>
 
+    <release version="3.1.0-5" date="2024-11-15">
+      <description>
+        <p>
+          Improve screenshots for flathub metadata.
+        </p>
+      </description>
+    </release>
+
     <release version="3.1.0-3" date="2024-11-10">
       <description>
         <p>