ux: reduce combobox item height

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Views/ConventionalCommitMessageBuilder.axaml

@@ -63,7 +63,7 @@
 
         <ComboBox.ItemTemplate>
           <DataTemplate DataType="m:ConventionalCommitType">
-            <Grid Height="24">
+            <Grid Height="22">
               <Grid.ColumnDefinitions>
                 <ColumnDefinition Width="Auto" SharedSizeGroup="NameColumn"/>
                 <ColumnDefinition Width="Auto" SharedSizeGroup="TypeColumn"/>