Fix sizes of icons in package card

CURA-8561

plugins/Marketplace/resources/qml/PackageCard.qml

@@ -148,8 +148,8 @@ Rectangle
         {
             id: externalLinkButton
 
-            Layout.preferredWidth: packageVersionLabel.height
-            Layout.preferredHeight: packageVersionLabel.height
+            Layout.preferredWidth: UM.Theme.getSize("card_tiny_icon").width
+            Layout.preferredHeight: UM.Theme.getSize("card_tiny_icon").height
             Layout.alignment: Qt.AlignTop
             iconSource: UM.Theme.getIcon("LinkExternal")
             hoverColor: UM.Theme.getColor("text_link")

resources/themes/cura-light/theme.json

@@ -556,7 +556,7 @@
 
         "card": [25.0, 8.75],
         "card_icon": [6.0, 6.0],
-        "card_tiny_icon": [1.2, 1.2],
+        "card_tiny_icon": [1.5, 1.5],
 
         "button": [4, 4],
         "button_icon": [2.5, 2.5],