Use spin rows rather than separate spin buttons

data/gtk/prefs.blp

@@ -13,46 +13,31 @@ template $RugbyPrefDialog : Adw.PreferencesDialog {
     Adw.PreferencesGroup {
       title: "Scoring";
 
-      Adw.ActionRow {
+      Adw.SpinRow try_spin {
         title: "Points for a converted try";
-
-        SpinButton try_spin {
-          adjustment: Adjustment {
-            lower: 1;
-            upper: 7;
-            step-increment: 1;
-          };
-          max-width-chars: 1;
-          valign: center;
-        }
+        adjustment: Adjustment {
+          lower: 1;
+          upper: 7;
+          step-increment: 1;
+        };
       }
 
-      Adw.ActionRow {
+      Adw.SpinRow utry_spin {
         title: "Points for an unconverted try";
-
-        SpinButton utry_spin {
-          adjustment: Adjustment {
-            lower: 1;
-            upper: 5;
-            step-increment: 1;
-          };
-          max-width-chars: 1;
-          valign: center;
-        }
+        adjustment: Adjustment {
+          lower: 1;
+          upper: 5;
+          step-increment: 1;
+        };
       }
 
-      Adw.ActionRow {
+      Adw.SpinRow kick_spin {
         title: "Points for a kick";
-
-        SpinButton kick_spin {
-          adjustment: Adjustment {
-            lower: 1;
-            upper: 3;
-            step-increment: 1;
-          };
-          max-width-chars: 1;
-          valign: center;
-        }
+        adjustment: Adjustment {
+          lower: 1;
+          upper: 3;
+          step-increment: 1;
+        };
       }
     }
   }