revert changes to old fluent button

Author: emmauss

src/Avalonia.Themes.Fluent/Controls/Button.xaml

@@ -37,13 +37,7 @@
                           ContentTemplate="{TemplateBinding ContentTemplate}"
                           Padding="{TemplateBinding Padding}"
                           HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
-                          VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" >
-          <ContentPresenter.Transitions>
-            <Transitions>
-              <BrushTransition Property="Background" Duration="0:0:0.083" />
-            </Transitions>
-          </ContentPresenter.Transitions>
-        </ContentPresenter>
+                          VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" />
       </ControlTemplate>
     </Setter>