test: fix flaky test_focus_on_click snaphot test

Remove the button animation in the `test_focus_on_click` snapshot test
causing flakiness in CI.

Author: TomJGooding

tests/snapshot_tests/__snapshots__/test_snapshots/test_focus_on_click.svg

@@ -4744,8 +4744,7 @@ async def action_clear(self) -> None:
 def test_focus_on_click(snap_compare) -> None:
     """Test focus on click may be prevented.
 
-    You should see a button in a non-focused stated
-
+    You should see a button in a non-focused state.
     """
 
     class NonFocusButton(Button):
@@ -4758,6 +4757,7 @@ def compose(self) -> ComposeResult:
             yield NonFocusButton("Click")
 
     async def run_before(pilot: Pilot) -> None:
+        pilot.app.query_one(NonFocusButton).active_effect_duration = 0
         await pilot.pause()
         await pilot.click(NonFocusButton)