Make small and very_small fonts actually smaller

Rather than the same as default_bold and default.
This also makes the extruder_icon font obsolete. Turns out it's actually just a very small font.

Contributes to issue CURA-5876.

resources/qml/ExtruderIcon.qml

@@ -49,7 +49,7 @@ Item
             id: extruderNumberText
             anchors.centerIn: parent
             text: index + 1
-            font: UM.Theme.getFont("extruder_icon")
+            font: UM.Theme.getFont("very_small")
             width: contentWidth
             height: contentHeight
             visible: extruderEnabled

resources/themes/cura-light/theme.json

@@ -41,12 +41,12 @@
             "family": "Noto Sans"
         },
         "small": {
-            "size": 1.0,
-            "weight": 63,
+            "size": 0.85,
+            "weight": 50,
             "family": "Noto Sans"
         },
         "very_small": {
-            "size": 1.0,
+            "size": 0.7,
             "weight": 50,
             "family": "Noto Sans"
         },
@@ -64,12 +64,6 @@
             "size": 1.15,
             "weight": 50,
             "family": "Noto Sans"
-        },
-        "extruder_icon":
-        {
-            "size": 0.7,
-            "weight": 50,
-            "family": "Noto Sans"
         }
     },