Unmark updateCheckTimerHandle as state()

The timer handle is internal logic, it doesn't affect displayed data and
shouldn't cause an update of the component.

Currently the value of the handle gets updated every `update_delay`
seconds causing lit component update process.

Release-Notes: skip
Change-Id: Ie00f58729feb6863d4cf460d44e5247c97c91153
diff --git a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts
index c02d474..f1ef362 100644
--- a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts
@@ -323,7 +323,6 @@
   @state()
   replyDisabled = true;
 
-  @state()
   private updateCheckTimerHandle?: number | null;
 
   @state() editMode = false;